Сколько сохнет стяжка пола из пескобетона: Сколько сохнет стяжка из пескобетона М300

Сколько сохнет стяжка из пескобетона в квартире, от чего зависит срок

При изготовлении стяжки традиционно применяют цементные или быстросохнущие гипсовые растворы. Промежуточное положение между ними занимает пескобетон – специальная сухая смесь на основе цемента М300. Среди ее компонентов – минеральные и химические добавки, придающие готовому покрытию прочность и долговечность.

Сколько сохнет пол и что влияет на скорость?

Выделяют две основные стадии: схватывание и полное застывание. Схватывается в течение 3-4 дней, а окончательно застывает через 28-30 дней, когда испарится вся влага. Практически столько же сохнет цементная стяжка, но схватывается она дольше – не менее недели.

Производители уверяют, что для проведения отделочных работ при условии применения сертифицированной сухой смеси не всегда важно, за сколько полностью высыхает конструкция. Например, при укладке плитки главное – выждать 7-10 дней и не создавать повышенных нагрузок, чтобы на поверхности основания не появились деформации. Другие финишные покрытия более требовательны к уровню влажности основания.

Только через 4 недели после заливки разрешается выполнять укладку ламината – иначе прессованная доска наберет влагу и вздуется. Линолеум монтируют не ранее 1,5 месяцев после бетонирования, иначе из-за сырости под ним может образоваться плесень. Через 5-6 недель после заливки базового слоя пескобетона настилают пробковый или дизайнерский наливной пол, которые требуют идеально ровного основания.

Отвечая на вопрос, сколько будет сохнуть стяжка, стоит отметить несколько факторов, влияющих на сроки ее готовности к отделке:

1. Состав компонентов, соблюдение пропорций при разведении согласно инструкции от производителя. При избытке воды пластичность смеси повышается, но прочность снижается, а высыхание затягивается.

2. Условия в помещении. Согласно предписаниям нормативных документов, оптимальные параметры таковы: уровень относительной влажности воздуха – 60-70%, отсутствие прямого солнечного света, температура в пределах +5-25°C.

3. Толщина слоя бетонирования. Если она не более 4-5 см, каждый сантиметр высыхает примерно неделю. Размер более 5 см продлевает застывание в два раза: каждые сверхнормативные 10 мм будут сохнуть 14 дней. Эта норма сохраняется и в том случае, если покрытие выполняется для заделки трещин и сколов, и высота его слоя неравномерная. Допустим, толщина стяжки 8 см, первые 5 см высохнут за месяц, а следующие 3 – за 6 недель.

4. Наличие подвала или цокольного этажа. При отсутствии в них вентиляции в бетон попадет конденсат. Если квартира находится на первом этаже, а подвала в доме нет, влага втягивается из грунта. В обоих случаях сушка происходит очень долго.

Как ускорить застывание стяжки?

Начать разговор стоит с предостережения. Чтобы сократить сроки готовности объекта, подрядчики (а иногда и те, кто решил самостоятельно провести ремонт), пытаются искусственно активизировать процедуру испарения влаги и созревания бетона. С этой целью ошибочно применяются следующие методы.

1. Устраиваются сквозняки в помещении, усиленно проветривается квартира. Способ категорически недопустим. Пока стяжка сохнет, ее защищают от прямого воздействия воздуха, чтобы вода испарялась постепенно – благодаря этому пол будет прочнее.
2. Включаются радиаторы или тепловентиляторы для повышения температуры в помещении. Влажность воздуха резко снижается, нарушается нормальный режим сушки – в результате появятся трещины или произойдет отделение верхнего слоя.

Пока стяжка пола высыхает, нежелательно даже попадание на поверхность прямых солнечных лучей: при этом одни участки пола затвердевают быстрее других, и происходит растрескивание.

Допустимые методы ускорения сушки состоят в использовании различных дополнительных компонентов:

1. Керамзита, базальта, пенополистирольных гранул. Они способны впитать половину воды из раствора, сделав мокрую стяжку полусухой. Если добавить керамзит, пескобетон застынет уже через 3 недели.
2. Средств, замедляющих схватывание в верхних слоях. За счет этого быстрее испаряется вода из нижних слоев.
3. Порообразователей. Благодаря им в бетоне появляются поры для отвода влаги, но применять препараты следует с осторожностью: они снижают прочность.
4. Модификаторов и пластификаторов, ускоряющих высыхание. Нередко ускорители изначально включены производителем в рецептуру. Если толщина стяжки с такими добавками не более 4 см, сохнет она 3-4 дня, позволяя начинать укладку ламината.

Чтобы сушка происходила быстрее, в частных домах и на первых этажах многоквартирных зданий обязательно настилают гидроизоляцию, чтобы исключить влияние грунтовой влаги. Если расчетная толщина превышает 5 см, заливку проводят в два этапа, сокращая сроки готовности в 2 раза.

Как проверить, высохла ли стяжка пола? По стандартам влажность определяется с помощью специальных гигрометров. Бетон застыл, если показания электронного прибора не выходят за пределы 3,4 %. Карбидный гигрометр должен показывать не более 2 %. Народный способ проверки таков: на пол кладут бумажную салфетку, накрывают ее целлофановым пакетом с песком или солью. Если через 10 часов салфетка увлажнилась, поверхность не готова к проведению отделочных работ.

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90000 The Ultimate Guide to Mortar Mix Ratios [Updated 2019] 90001 90002 This page is part of our blog and is all about mortar mixes for home improvement and construction projects. 90003 90002 Whether you’re laying bricks, pointing, renewing chimney flaunching, laying screed or rendering, we have the best mix ratios for you. 90003 90002 Tradespeople and builders often use different terms to describe cement, concrete and mortar, so here’s a quick guide designed to avoid confusion: 90003 90002 90009 Cement 90010 is a greyish coloured powder that is mixed with sand and / or other aggregates to create concrete or mortar.90003 90002 90009 Mortar 90010 is a mixture of fine sand particles, cement, water and sometimes lime. It’s typically used for brick laying and pointing. It is usually laid in thin layers as thicker layers may crack during the drying process. 90003 90002 90009 Concrete 90010 is a mixture of aggregates such as crushed rock, gravel and sand that is mixed with cement and water. Concrete is usually laid in thick layers, the larger particles prevent cracking during the drying process. 90003 90002 90009 Soft sand 90010 is also known as building sand and contains fine grains of sand and is used for bricklaying, pointing and where thin layers of mortar are required.90003 90002 90009 Sharp sand 90010 is more coarse than building / soft sand and is perfect for mixing with other sands to prevent cracking during the drying process. It’s often used in situations where a slightly thicker layer of mortar is required — chimney flaunching, bedding roof tiles and many garden projects will require sharp sand. 90003 90002 90009 Plasterers sand 90010 is not as coarse as sharp sand but not as fine as soft sand. It’s washed to remove salts and clay residue that could cause efflorescence (salting).90003 90002 90009 Lime 90010 can be used as an alternative to cement in some mixes or used in conjunction with it. Lime allows materials such as bricks to breathe, it’s commonly used on older period buildings with soft, permeable bricks that would likely crack if cement was used. 90003 90002 90009 Plasticiser 90010 is a liquid that is added to the mix to make the material easier to work with and it also slows down the curing process slightly. It makes a typical mortar mix sticky and easier to point over.90003 90002 90009 Waterproofer 90010 is different to plasticiser. Does what it says on the tin and is often used when rendering. 90003 90002 90009 Frost proofers, accelerators and colour additives 90010 can be included in the mix as required. 90003 90048 Related Products Hand-Selected by Us 90049 90002 We think you might like these products: 90003 90052 Wolfcraft Mixer Paddle 90053 90002 90055 90003 90002 Make cement and plaster mixing easy with this heavy-duty mixer paddle. Suitable for most electric drills.90058 Check Price Here 90003 90052 60 Litre H / Duty Mixing Tub 90053 90002 90063 90003 90002 Perfect for mixing small amounts of cement or plaster in confined spaces, less mess and easy storage. 90058 Check Price Here 90003 90052 70 Litre Electric Mixer 90053 90002 90071 90003 90002 With an impressive 70 litre capacity, this electric mixer will save you time on any job, large or small. 90058 Check Price Here 90003 90052 60 Litre H / Duty Mixing Tub 90053 90002 90079 90003 90002 Perfect for DIYers and those on a limited budget is this 5-piece trowel set by Draper Redline.90058 Check Price Here 90003 90052 What Happens if You Make the Mortar Too Weak? 90053 90002 Not only will the mortar fail to bind sufficiently, it may also crumble after a short amount of time or wash away after minimal weathering. 90003 90002 The photo below shows a ridge tile that was bedded onto a very weak and totally unsuitable mortar mix. 90003 90002 The tile was not secured in place and the «mortar» could be crushed into small particles by simply squeezing it in my hand: 90003 90002 90093 90003 90052 What Happens if the Mix is ​​Too Strong? 90053 90002 Too strong a mix, i.e made with too much cement and your mortar may dry too quickly, shrink and crack. 90003 90002 Cracking can be avoided by reducing the amount of cement in the mixture and ensuring the mortar is wet enough. 90003 90002 The photo below shows cracked mortar — typical issues that can occur if the mix is ​​too strong: 90003 90002 90104 90003 90052 Best Mortar Mixes 90053 90002 Below you’ll find our guide to mortar mixes: 90003 90110 Bricklaying 90111 90002 The best mix will depend on the type of brick and the location of the wall.For most domestic builds such as house building, use one of these mixes: 90003 90002 4 parts soft sand with 1 part cement, add water and plasticiser. 90003 90002 For soft older bricks already bedded onto a lime based mortar; a lime and sand mix should be used, the ratio will depend on the type of lime and how much water content it has. This page has more detailed information about lime / sand ratios. 90003 90002 For retaining walls or anywhere likely to be in regular contact with water, 3 parts soft sand and one part cement, 1 part lime is optional depending on the type of brick / block.90003 90002 For Airtec blocks above DPC, 6 parts soft sand, 1 part cement and 1 part plasticiser or 5 parts soft sand and 1 part cement. 90003 90002 For blocks below DPC, 4.5 parts soft sand, 1 part cement and 1 part lime or 4 parts soft sand and 1 part cement 90003 90002 This page contains a price guide for wall repointing. 90003 90110 Chimneys 90111 90002 For chimney repointing to a modern home, the best mix will depend on how exposed the chimney is and it’s location. For chimneys in wind swept rainy parts of the country use a mix of 3 parts soft sand and 1 part cement.For softer or more permeable bricks, 4 parts sand, half part cement and 1 part lime can be used. Plasticiser is optional. 90003 90002 Chimney flaunching will receive a lot of rainfall so the mix should be strong, this prevents it washing out. Because flaunching is laid several inches thick, add sharp sand to the mix to avoid cracking during the drying process. 2 or 3 parts soft sand 1 part sharp sand, 1 cement and half-part lime is optional. 90003 90002 or 90003 90002 1 part soft sand, 2 parts sharp sand, 1 cement, half part lime is optional.90003 90002 For older period homes, a lime-based should be used instead of cement. 90003 90002 Chimney maintenance costs are published on this page. 90003 90110 Paving Mortar Mix 90111 90002 For bedding under the slabs use 5 parts sharp sand, 1 part soft sand and 1 cement. 90003 90002 For pointing use 4 parts soft sand and 1 part cement. For high traffic areas, a stronger mix of 3 parts soft sand and 1 part cement can be used. 90003 90002 This page contains a price guide for a new patio. 90003 90110 Render Mortar Mix (Modern Buildings) 90111 90002 The first coat of render should ideally be slightly stronger than the second coat.While some tradespeople make the two mixes the same strength, the second coat should never be stronger than the first coat. 90003 90002 A pure soft sand mix should not be used when rendering. It’s preferable to use either sharp sand, plasterers sand or a mixture of two. Soft sand can be added to the mix but we feel it should not comprise more than 25% of the entire mix. 90003 90002 The first coat of render can be 2 parts plasterers sand and 2 parts sharp sand, 1 part cement and half part lime. Waterproofer can be applied to the first coat if the property is modern.90003 90002 The second coat must be slightly weaker than the first, so 3 parts plasterers sand, 2 parts sharp sand, 1 part cement and half lime. Plasticiser can be used in the second coat. 90003 90002 For locations in the east and south of the country or any sheltered location that experiences less windswept rain, a slightly weaker mix can be used. For the first coat 4 parts sharp / plasterers and for the second coat 5 parts sharp / plasterers. 90003 90002 This page contains a guide to rendering prices in the UK.90003 90052 Render (Period buildings) 90053 90002 Modern buildings are constructed with thermal efficiency in mind and sealants, waterproofing materials and cement based products can be used. 90003 90002 Period properties are designed to breathe. Floors and walls are often constructed with lime, a material that lets the moisture in the building escape. Covering breathable materials with non-breathable cement, gypsum plaster or waterproofing sealers can lead to significant damp problems. 90003 90002 For period properties we suggest seeking the advice of a specialist who understands how older buildings are designed to breathe.90003 90110 Floor Screed Mix 90111 90002 For modern homes: 4 parts sharp sand and 1 part cement. Although anything from 3-5 parts sharp sand to 1 part sand would be acceptable for most situations. 90003 90002 For period buildings: Lay a lime-based screed as the floor needs to breathe. If you do not, the cement in the screed will push moisture towards the walls where the soft bricks and plaster will absorb the water. 90003 90110 Best Mortar Mix For Roof Tiles 90111 90002 Because roof tiles are located in an exposed location that’s likely to experience rainfall, a strong mix should be used.Unfortunately, some profiled roof tiles require a very thick bedding of mortar, so to reduce the risk of cracking, sharp sand should be introduced to the mix for most tiles. 90003 90002 All tiles except Plain tiles — 2 parts soft sand, 1 part sharp sand and 1 part cement. 90003 90002 For tiles where only a thin bedding of mortar is required (i.e. Plain tiles) 3 parts soft sand *, 1 part cement and plasticiser. 90003 90002 * we recommend choosing a soft sand that is fairly coarse, avoid soft sands that are at the «silty» end of the spectrum.90003 90002 90009 Do not forget; 90010 to meet new British Standards requirements for roof fixings, you can not rely on mortar to secure the tiles in place. Ridges, valley tiles and verges should be secured with a nail or clip, either in addition to the mortar in replacement of it, this is called a dry fix method. This page contains information about the differences between a dry and wet fixing method. 90003 90002 Roof repair prices can be located on our main price list here. 90003 90052 How Much Water is Too Much? 90053 90002 The firmness of the wet mortar can be altered by changing the type of sand, the sand / cement ratio and the amount of water added to the mix.90003 90002 Most bricks and blocks are quite porous and as only a thin layer of mortar is required, a wet or «sloppy» mix is ​​often preferable. 90003 90002 Some roof tiles require a bedding layer of mortar that’s several inches thick and a wet / sloppy mix would not be suitable, it would slump off the tile. For roofing projects, a firmer mixture is generally required. 90003 90002 Needless to say that mortar should never be so firm that it does not have enough water content to create a chemical reaction.Neither should it be so sloppy that it’s impossible to work with. 90003 90052 What’s the Lowest Temperature I Can Use Mortar? 90053 90002 5 degrees is the lowest temperature that mortar can be laid. Any colder and there is a risk of frost which will weaken the finished mortar. Frost proofers can be added to the mortar but should not be relied upon. 90003 90052 Additives 90053 90002 90009 Frost proofer 90010 should not be relied upon to protect mortar from freezing conditions. It can be used but its reliability is debatable.90003 90002 90009 Colourants 90010 can be used but only use as much as you need and avoid excessive amounts. 90003 90002 90009 Accelerators 90010 speed up the drying time but often leave you with little time to work with the mortar before it starts to set. If you continue to work with a mortar that has set, you’ll reduce the strength of the finished mortar. Therefore, you should only use them when absolutely necessary and not as a matter of course. 90003 90052 Concrete and Ready Mix Prices 90053 90002 If you do not want to mix the materials yourself, you can get it delivered by a ready mix supplier.90003 90002 This is the perfect option for large projects. 90003 90002 See ready mix concrete prices here. 90003 90048 Related Hand Selected by Us 90049 90002 We think you might like these products: 90003 90052 Wolfcraft Mixer Paddle 90053 90002 90055 90003 90002 Make cement and plaster mixing easy with this heavy-duty mixer paddle. Suitable for most electric drills. 90058 Check Price Here 90003 90052 60 Litre H / Duty Mixing Tub 90053 90002 90063 90003 90002 Perfect for mixing small amounts of cement or plaster in confined spaces, less mess and easy storage.90058 Check Price Here 90003 90052 70 Litre Electric Mixer 90053 90002 90071 90003 90002 With an impressive 70 litre capacity, this electric mixer will save you time on any job, large or small. 90058 Check Price Here 90003 90052 60 Litre H / Duty Mixing Tub 90053 90002 90079 90003 90002 Perfect for DIYers and those on a limited budget is this 5-piece trowel set by Draper Redline. 90058 Check Price Here 90003 90264.90000 A Screed Masterclass | Homebuilding 90001 90002 Very occasionally in the world of house construction a time-honoured way of doing things suddenly changes. But it takes a lot to uproot tried and tested methods. Builders are not keen on risking changing something that works well. 90003 90002 For something new to catch on there needs to be a compelling reason, usually in terms of cost or time saving. Sometimes the impetus is driven by changes to the Building Regs, such as meeting stiff thermal insulation targets, or architects may start specifying something en-masse that’s of demonstrably improved quality or performance.90003 90006 The Rise of Liquid Screeds 90007 90002 Either way, we may be about to witness one such ‘sea change’ in the normally sedate world of floor screeds with the rise of liquid screeds. 90003 90002 There’s no law that says you have to cover your ground floor structure with a screed before laying floor coverings. Screeds are not structural. For example, in garage conversions it’s common for floorboards to be placed over thick sheets of insulation. 90003 90002 One of the main reasons screeds are used in the vast majority of homes, despite the extra expense, is that 90013 they’re very useful for levelling uneven floor structures 90014.This is particularly important with modern precast concrete beam and block floors, which have a distinct camber that can cause problems when it comes to laying floor finishes. 90003 90002 Screeds are also the 90013 preferred medium for underfloor heating pipes 90014 as the material excels at absorbing and radiating warmth, becoming an integral part of the heating process. 90003 90002 Conventional sand / cement screed uses a relatively strong mix (1: 3 cement to sharp sand) with a fairly dry, almost powdery consistency.Traditionally it would be prepared on site but shovelling sand and cement into a mixer is very labour intensive and prone to inconsistency, which is why most larger sites now use ready-mixed screeds delivered by lorry, in a similar way to foundations. 90003 90002 Ready-mixed screeds also come with added retardants to delay the set, so a single load can last all day. But despite such improvements in quality, poured liquid screeds installed by specialist firms are starting to make major inroads into a market dominated until now by traditional sand and cement.90003 90002 Ashley Sexton, director of Express Liquid Screeds, says: «There’s been a huge increase in the popularity of pumped anhydrite screeds over the last five years; it’s estimated they now account for nearly 20% of the market, «he says. 90003 90002 The terminology can be a little confusing because the terms ‘anhydrite’, ‘calcium sulphate’ and ‘gypsum’ are used interchangeably. The key ingredient is anhydrous (dry) calcium sulphate, typically comprising around 35% recycled content. When mixed with water this forms gypsum, the same material found in modern plasters and plasterboard.The gypsum replaces conventional cement as a binder. 90003 90002 Cement also seems to be making something of a comeback. Andy Vincent from Screed Giant says: «The market has been shaken up in last six months as calcium sulphate has been joined by new cement-based products like McGraths ‘Cemfloor and Tarmac’s Belitex.» These claim to offer similar benefits to gypsum but without the downsides. So, what’s best? 90003 90006 The Pros and Cons 90007 90002 90013 Sand / Cement 90014 90003 90002 Old-fashioned sand / cement screed is 90013 relatively cheap to produce 90014 and place as it can be prepared by unskilled labour and trowelled on site.It also requires 90013 minimal preparation 90014 other than taping joints between insulation boards. And unlike poured liquid screeds, sand / cement readily lends itself to the formation of 90013 sloping floors 90014 in wetrooms. 90003 90002 The downside is often 90013 patchy quality, uneven finish and a propensity to develop cracks 90014. Where floors are uneven, a self-levelling compound may need to be applied before floor tiling. To avoid cracking, manually applied screeds are commonly laid in 5m-long bays, sometimes with anti-crack mesh or fibres added.90003 90002 Although it’s compatible with UFH, hand-mixed sand / cement is not ideally suited as it’s relatively thick (typically laid 65mm to 75mm deep) and prone to harbouring pockets of air that can act as a barrier to heat transfer. Using ready mix improves the consistency but adds to the cost, and unless skilfully applied the quality can still be mediocre. 90003 90002 As a rough guide, laying a conventional screed costs around £ 15 / m2, increasing by around £ 5 / m2 when delivered ready-mixed. 90003 90002 90013 Pumped Anhydrite Screeds 90014 90003 90002 Anhydrite (liquid calcium sulphate) screeds offer a number of advantages: 90003 90058 90059 They’re not much dearer than ready-mix sand / cement, costing around £ 25 / m3 (laid to a 50mm depth).90060 90059 Although the material itself costs about 50% more per m3 than sand / cement, being poured from a large hose makes it much quicker to lay (it’s claimed 20 times as quick) with consequent savings on labour. 90060 90059 Costs are also reduced because it 90013 can be applied at depths as thin as 35mm 90014. With underfloor heating you typically need 30mm cover above UFH pipes, making about 45mm in total, still incredibly slim by conventional standards. 90060 90059 Pumped liquid screeds are effectively 90013 self-levelling and self-curing 90014, which translates into a nice level finish.While traditional sand / cement screeds aim to achieve the standard known as ‘SR3’, which permits a 10mm difference over 2m, liquid screeds aim for perfection (SR1 standard) but guarantee SR2 with a variation of plus or minus 5mm. Quality is further assured as liquid screeds are applied by specialist approved contractors. 90060 90059 Anhydrite is far 90013 less prone to shrinkage 90014 than cement and needs far fewer expansion joints (just across some doorway thresholds). This makes it compatible with large stone tiles that can be vulnerable to cracking should the screed beneath them shrink.90060 90059 Best of all, liquid screeds are 90013 ideally suited to UFH 90014 because the liquid envelopes the pipes eliminating voids, so enhancing heat transfer between the pipes and the screed. Also the slimmer covering over pipes allows a quicker reaction time with better response / controllability. 90060 90079 90002 One downside of anhydrites is that you need to prepare the surface by sanding prior to tiling. 90003 90002 90013 Pumped Liquid Cement-Based Screeds 90014 90003 90002 Liquid cement screeds are applied in the same way as anhydrite and laid to the same thickness.They have similar properties to anhydrite: they are 90013 self-compacting, quick to lay and UFH-compatible 90014. Manufacturers claim they are quicker to dry, even in adverse conditions, and can be tiled with little or no surface preparation. 90003 90002 However, they’re relatively new to the UK and so far there’s 90013 little hard evidence to substantiate performance 90014, although they’ve achieved a successful track record abroad. They’re also about 20% dearer in terms of materials, although costs may fall as demand rises.90003 90006 Preparing the Floor 90007 90002 With liquid screeds of all types it’s essential to get the preparation right: 90003 90058 90059 The floor needs to be ‘tanked’ like a mini swimming pool using a polythene sheet membrane (typically 500 gauge). Here, a 500 gauge ‘tanking’ membrane is laid over the insulation with joints taped and tracks laid ready for underfloor heating. 90060 90079 90058 90059 In most cases the surface to be screeded will consist of 50 to 100mm-thick layers of insulation boards over a DPM (damp-proof membrane) on top of the floor structure.It’s important these sheets are stable when walked on and laid so they do not rock about on uneven sub-floors. 90060 90059 This base layer of insulation needs to be lined with polythene sheeting to stop the liquid escaping and, in a worst-case scenario, causing the insulation boards to lift up and float around the room. 90060 90059 Lining also helps prevent any potential chemical reaction with the insulation underneath. 90060 90059 Any rogue plumbing or obstacles may need temporary formwork placed around them to ensure 100% watertightness.90060 90059 To contain the liquid, the polythene sheet membrane is then lapped up the walls in a sharp right angle and glued in place with spray adhesive. This is in addition to existing layers such as the damp-proof course / damp-proof membrane, insulation strips around wall edges, and thin strips of compressible foam designed to accommodate any expansion once the screed is dry. 90060 90059 The final job is to tape all the joints and scrape off any lumps of plaster or debris so they do not float up to the surface once the screed is poured.90060 90059 If you’re installing UFH it’s essential the pipes are pressurised to weigh them down and they’re securely fixed over the polythene membrane to prevent them lifting up and floating as the screed is poured. 90060 90079 90002 With liquid screeds, it’s easy to underestimate the volume of material required if the floor structure is uneven. For example, the camber in beam and block floors means that the point you measure from might be a bit higher or lower than the median. So you might order 50mm depth and find it actually ranges from 40mm to 70mm.90003 90006 Applying the Screed 90007 90002 The installers usually arrive on site a couple of hours in advance to set up their pump and check floor measurements to ensure the amount of screed ordered will be sufficient. Working from a level datum point, such as the base of the stairs or a doorway, a number of tripod levelling gauges are placed around the floor at various points and with the help of a laser adjusted to a consistent depth, thereby ensuring the finished screed surface is level throughout.90003 90002 Once the mixer truck arrives the pre-mixed pumped screed is poured from a hefty-looking hose until the surface level reaches the marker tripods, which are then removed. It generally takes less than an hour to lay an entire ground floor in an average new house. 90003 90002 To make sure the screed is smooth and level with no air bubbles, the freshly applied screed is briefly manually agitated by someone wading through using a ‘dappling bar’. 90003 90006 Tiling and Floor Coverings 90007 90002 Sand / cement screeds are usually a bit dusty or sandy on the surface due to precipitation or poor mixing so they tend to need a firm brushing before priming and tiling.90003 90002 Calcium sulphate screeds are more demanding in this respect, because as the anhydrite cures a fragile coating of fine particles known as ‘laitance’ is deposited on the surface along with any bits of debris that may have floated up. This weak surface film is too friable and flaky to tile onto and needs to be abraded by sanding after about five to 10 days and the dust vacuumed off. Not doing this so is a major cause of failure with floor tiles, as it can peel off. Having this sanding done professionally can add around £ 8 / m2 to the cost.90003 90002 However, there are some new ‘low laitance’ varieties that only require a stiff brush or light sanding with 60 grit sandpaper. Problems can develop if the laitance is left for too long, as it becomes harder to remove and can also hinder the drying process. This is not such an issue if you plan to lay unbonded flooring without adhesive, such engineered timber boards. But before tiling it’s essential that floors are free of loose particles and primed to seal porous surfaces and prevent suction of moisture.90003 90002 You also need to use special anhydrite-compatible tile adhesives that do not chemically react with gypsum, such as AnhyFix or Keracoll h50. 90003 90006 New Varieties of Screeds 90007 90002 Manufacturers like Tarmac provide specially formulated products such as Topflow Soundbar — an acoustic screed originally designed to improve sound insulation between flats. These can be placed on top of timber floors, first having been strengthened with a layer of resilient foam under 24mm-thick chipboard.90003 90002 For use with underfloor heating, specially formulated Thermio Plus only needs a super-thin 20mm covering over the pipes, making it more efficient at conducting heat into the room with quicker response times to temperature changes and reduced drying times. Other specialist screeds have been developed for use with Lewis Deck dovetail sheeting, for underfloor heating and acoustics on timber joisted upper floors. 90003 90006 The Future 90007 90002 Small developers have long wanted to use liquid screeds, especially with underfloor heating.But sand / cement will still be around because pumped screeds are only cost-effective on floors areas of at least 40m2. For many smaller home extensions, floors will continue to be laid in the traditional way for the foreseeable future. 90003 90006 Drying Out Times 90007 90002 90013 Conventional sand / cement and anhydrite screeds 90014 90003 90002 You can walk on the floor after about 48 hours once it becomes solid. Normal site traffic can resume after about a week and partition walls erected.Another week and a kitchen can be fitted. The image shows Thermo Plus, which has a distinctive tan colour. The liquid floor is perfectly level and should be walkable in 48 hours. 90003 90002 Unfortunately you can not lay floor coverings until the screed is 100% dried out all the way through. Allow a day for every mm depth up to the first 40mm, then two days per mm. The optimum drying conditions would be an ambient temperature of around 20 ° C and well-ventilated rooms (windows must be closed for the first 72 hours to prevent draughts causing over-rapid drying).90003 90002 To be sure the floor has fully dried (less than 75% relative humidity or 0.5% moisture content) a special hydrometer can be used. In some cases it may be acceptable to lay impermeable floor tiles a little sooner. 90003 90002 Several factors affect drying times: 90003 90058 90059 With sand / cement, specifying a modified admixture can speed things up so floor coverings can be down in about three weeks. 90060 90059 Anhydrites are very sensitive to drying conditions — it helps if the walls are plastered and dried out first so that room moisture levels are not too high.90060 90059 If time is short the process can be speeded up using ‘force drying’ techniques, shrinking drying times to less than 40 days. 90060 90059 Dehumidifiers can be used to accelerate drying 72 hours after placing. 90060 90059 After the first week UFH can be set to its lowest temperature and gradually turned up by 3 ° C per day until the working temperature is reached. 90060 90079 90002 90013 Cement liquid screeds 90014 90003 90002 Their drying times are claimed to be as short as two to three weeks for a 40mm thick floor with good drying conditions, compared to around 40 days with calcium sulphate.They can also be force-dried and will not re-absorb moisture, so are more reliable in poor drying conditions. 90003 .90000 Floors and Flooring — SANS10400-Building Regulations South Africa 90001 Sunday, July 12 2020 90002 90003 About Us 90004 90003 Contact Us 90004 90003 Terms & Conditions 90004 90009 90002 90003 Building Regulations (NBR) Intro. 90002 90003 Why National Building Regulations 90004 90003 The PAJA: A Law to Protect Your Rights 90004 90003 Housing Consumers Protection Measures Act 90004 90003 House Plan Submissions 90004 90003 Municipality Contact 90002 90003 Planning and Building By-Law Definitions 90004 90009 90004 90003 Zoning Schemes 90002 90003 Cape Town Zoning Scheme 90004 90003 Town Planning Scheme — JHB 90004 90003 Tshwane Town Planning Scheme 2008 90004 90009 90004 90003 National Building Regulations Glossary 90002 90003 Town Planning Definitions 90004 90003 Environmental A to Z 90004 90009 90004 90009 90004 90003 NBRs (SA) 90002 90003 Construction Laws & SANS 10400 90004 90003 Building Regulations Section 1 90002 90003 General Principles & Requirements-Part A 90004 90003 Structural Design-Part B 90004 90003 Dimensions-Part C 90004 90003 Public Safety-Part D 90004 90003 Demolition Work-Part E 90004 90003 Site Operations-Part F 90004 90003 Excavations-Part G 90004 90003 Foundations-Part H 90002 90003 Tree Damage to Walls & Foundations — SANS10400-H Annex-D 90004 90009 90004 90009 90004 90003 Building Regulations Section 2 90002 90003 Floors-Part J 90004 90003 Walls-Part K 90004 90003 Roofs Part-L 90004 90003 Stairways-Part M 90004 90003 Glazing-Part N 90004 90003 Lighting and Ventilation-Part O 90004 90003 Drainage-Part P 90004 90003 Non-Water-Borne Sanitary Disposal-Part Q 90004 90009 90004 90003 Building Regulations Section 3 90002 90003 Stormwater Disposal-Part R 90004 90003 Facilities for Disabled People-Part S 90004 90003 Fire Protection-Part T 90004 90003 Refuse Disposal-Part U 90004 90003 Space Heating-Part V 90004 90003 Fire Installation-Part W 90004 90003 Energy Usage & Sustainability (SANS 10400X & XA) 90002 90003 Fenestration Calculations 90004 90009 90004 90009 90004 90009 90004 90003 Construction Elements 90002 90003 Concrete Foundations 90004 90003 Concrete & Masonry 90002 90003 Concrete Mixes 90004 90003 Concrete Mixes by Weight and Volume 90004 90003 Concrete Slab 90004 90003 Concrete in Cold Weather 90004 90009 90004 90003 Glass and Glazing as a Construction Element 90004 90003 Roofs and Roofing 90002 90003 Anchor Roof Structure 90004 90003 Thatch Roofs and Lightning 90004 90003 Waterproofing Roofs 90004 90009 90004 90003 A Guide to SANS 10400XA 90004 90003 Facilities for Disabled Persons 90004 90003 90004 90009 90004 90009.90000 How to Rapidly Speed ​​up Concrete Drying Time 90001 90002 How Long Does Concrete Take to Dry? 90003 90004 90005 According to the Portland Cement Association, 90006 90007 once conditions are conducive for the concrete to dry 90008 90009 — that is, consistent, reasonable heat in the air and low relative humidity — it typically takes about 30 days for every one inch of slab thickness to dry to 85-90% relative humidity. We say ‘once conditions are conducive’ because concrete that was put down a year ago might have been exposed to the elements for eleven months and only enclosed for the last month.If so, it has only been drying for one month. 90010 90004 Since concrete drying time is a major factor in the schedule of most construction projects, shortening that time can potentially save you a lot of money. 90010 90004 When a flooring system will be installed over the concrete slab, drying is critical. If the slab is not sufficiently dry when the floor is installed, the floor might be seriously damaged by the excess moisture. 90010 90015 Tips on How to Speed ​​Up Concrete Drying Time: 90016 90017 90018 Use the correct amount of water in the mix.Too much water can increase the drying time. 90019 90018 Do not over-trowel or seal the surface. This can block the pores in the concrete, diminish moisture evaporation, and increase the drying time. 90019 90018 Keep doors and windows closed, the HVAC running, and fans circulating the air. 90019 90018 You can also use dehumidifiers to remove moisture from the air. This will speed up the overall drying process of the slab. 90019 90026 90015 The Difference Between Curing and Drying 90016 90004 Concrete curing and concrete drying are two different processes.Curing is the process of hardening that begins immediately after the concrete is poured. The concrete curing process is usually mostly complete after 28 days or so. However, the concrete will continue to harden further for a significant amount of time after that. 90010 90004 Even after the concrete is cured, excess water still must evaporate from the concrete. While it only takes around 28 days to cure concrete, drying can take months. The general rule of thumb is that concrete takes about 30 days to dry for every one inch of slab thickness.However, as we pointed out above, the conditions need to be right. That is, you’ll need low ambient relative humidity and a consistently warm temperature. You can achieve this by enclosing the space and then turning on the HVAC. 90010 90015 How Concrete Cures 90016 90004 There are many types of concrete, but they all contain three basic components: cement, aggregate, and water. 90010 90004 When water and cement are mixed, a chemical reaction occurs that binds them together. This is what causes concrete to harden.In the process, the concrete becomes porous and a certain amount of this water becomes part of the concrete. The water that’s leftover either evaporates or remains in the capillaries of the concrete. 90010 90015 How Concrete Dries 90016 90004 Concrete dries as the water inside it evaporates through its surface. As this water evaporates through the surface, water from deep within the concrete moves through the capillaries and up to the surface to replace it. As long as the surrounding air can hold more water vapor, evaporation continues.When the surrounding air can not hold any more water vapor, evaporation or drying of the concrete stops. 90010 90002 How to Speed ​​Up Drying: Before the Pour 90003 90045 90004 90007 Admixtures or the right balance of water can greatly help decrease drying times. 90008 90010 90004 There are a few things you can do before you pour the concrete that will speed up the drying process: 90010 90052 90018 90052 90018 Use the correct amount of water in the mix. If there’s too much water, there will be more water left over after curing that will need to evaporate.That means a longer drying time. 90019 90018 You can use a high cement content mix to reduce the drying time. However, there is the risk of cracking due to shrinkage. 90019 90018 Are you using lightweight concrete? Lightweight aggregates absorb a lot of water and this increases the drying time. You can reduce the drying time by replacing these lightweight aggregates with synthetic aggregates that do not absorb water. 90019 90018 If possible, do not use curing, sealing, or bond-breaking agents.They can inhibit evaporation from the concrete’s surface which increases the drying time. 90019 90063 90019 90063 90002 How to Speed ​​Up Drying: After the Pour 90003 90068 90004 90007 After you pour, the strategy for drying changes. 90008 90010 90004 Once the slab has cured, enclose the space as soon as possible to protect the slab from absorbing any additional moisture. 90010 90004 While protecting the slab from additional moisture is important, there are a couple of other factors that affect drying after the pour: 90010 90052 90018 The ambient relative humidity and temperature of the air 90019 90018 The temperature of the slab itself 90019 90063 90004 The ambient relative humidity is important because it controls whether water can evaporate from the slab.If the ambient relative humidity is too high, your slab will not be able to dry. 90010 90004 Enclosing the space allows you to use HVAC to control ambient conditions. In cooling mode, HVAC systems act like a refrigerating dehumidifier and will usually maintain a 50% relative humidity level, which is perfect for drying concrete. In heating mode, they lower the relative humidity by raising the air temperature. 90010 90004 HVAC systems are also a great way to get air circulating around the concrete and thereby reducing drying time.90010 90089 90004 90007 To really speed up concrete drying time, enclose your slab and ensure the HVAC system is on. 90008 90010 90015 Dehumidifiers 90016 90004 Some facilities have central dehumidifiers that can be used to speed up the drying process. You can also rent portable dehumidifiers and even fans. 90010 90004 Both centrally installed and portable units are available that use one of these methods. 90010 90015 Testing the Concrete for Dryness 90016 90004 You can not tell if concrete is dry just by looking at its surface because the surface is nearly always drier than the center of the slab.The only way to know if concrete is dry is to test it. 90010 90004 Concrete moisture testing has been going on since the 1960s and today there’s a scientifically proven way to easily test the moisture content of a concrete slab. The test is called «the relative humidity test using in situ probes» and is the basis for the ASTM F2170 standard. 90010 90004 The test uses sensors — inserted into the concrete at specific depths — to measure the relative humidity of the air trapped in the concrete.For slabs drying on one side only, the sensors are inserted to a depth that’s 40% of the slab’s thickness. For slabs drying on both sides, the sensors are inserted to a depth that’s 20% of the slab’s thickness. 90010 90004 The Wagner Meters Rapid RH® L6 system is an in situ relative humidity testing system that conforms precisely to the ASTM F2170 standard. The single-use L6 sensors are factory calibrated and easy to use. Once they’ve been installed in the slab and allowed to equilibrate for 24 hours, you can take repeated moisture readings whenever you want.Unlike reusable probes, the L6 sensors never need recalibration. 90010 90002 How Do You Know When the Concrete Is Dry? 90003 90004 You do not unless you test it. If you’re lucky, it will be dry. However, many times it will not be, so you’ll need to give it some more time to dry and then test it again. How much time you’ll give it to dry before testing again is pretty much a best guess based on past experience. At some point, the slab will be dry enough to receive the floor covering. Of course, this is an unpredictable process and because of that schedules can slip and costs can mount up.90010 90004 When you absolutely must install the floor covering but the drying process is not complete, you can use a moisture mitigation system. If you go this route make sure you choose a high-quality product that will adequately seal the moisture into the slab. 90010 90015 New Technology for Data Logging and Trend Analysis 90016 90004 Technology is now available that adds some science to the art of predicting concrete drying time. 90119 It’s called data logging. 90010 90004 Data logging involves installing small devices into the concrete.These devices have the ability to continuously monitor concrete moisture levels as well as the ambient temperature and relative humidity. The collected data is stored in their memory and whenever you visit the site you can easily download it via an app on your smart device. 90010 90004 This data can give you important insight into the drying process. For example, if a change in ambient conditions is likely to delay the drying process, you’ll be able to spot it and correct it sooner. Of course, you’ll also be able to easily see who’s responsible for it.(Hint: It will not be the installer.) So, if the schedule gets delayed, you’ll have the data to protect you from liability. 90010 90004 While the Wagner [RH] probe takes only about a minute to read, the others take 2 hours to read. So if there 20 probes to be read, I can read the Wagner probes in 30 minutes, while it takes about 40 hours to read the other type of probe. I can find better things to do than stand around and wait 40 hours in order to read those probes. 90010 John LowtherJKL Construction 90004 Also, when you have complete concrete moisture data, you can perform trend analyses.This is where you look at data on a chart, see a trend, and then project how you think it will continue. This will allow you to more accurately estimate when the drying process will be complete. The more data you gather from all projects, the more accurate your drying estimates will become. This will help you schedule your next steps in the construction process, saving you both time and money. 90010 90015 The Tools for Data Logging and Trend Analysis 90016 90004 Data logging for concrete drying requires a system that integrates concrete moisture testing with automated data logging.90010 90004 The Rapid RH L6 system has the most advanced data logging technology available. There are two battery-powered devices that automatically log data: the DataGrabber® and the DataGrabber with Bluetooth®. 90010 90004 The DataMaster ™ L6 app runs on any iOS or Android device and can download the logged data from either the DataGrabber with Bluetooth or the DataGrabber using the Total Reader®. 90010 90004 The DataMaster L6 app stores, displays, reports, and emails the data in PDF format.For data integrity, accuracy, and peace of mind, backups of the logged data are stored in both the cloud and in the sensors installed in the slab. 90010 90004 For monitoring ambient conditions, the Wagner Meters Smart Logger ™ records both the ambient temperature and the relative humidity for 300 days of replaceable battery life or up to 12,000 readings. The Smart Logger app can then download this logged data via Bluetooth for you to store, report, or share with others via email. 90010 90004 Used together, the DataMaster L6 app and the Wagner Meters Smart Logger are a complete concrete moisture testing and ambient condition logging system.90010 90015 Conclusion 90016 90004 To sum up … 90010 90004 The only way to know if a concrete slab is dry is to test it. The most accurate test for doing this is the in situ relative humidity test. 90010 90004 Data logging throughout the drying process allows you to detect drying problems early, correct them, and will aid you to determine what is responsible for slow drying. This protects you from liability. 90119 Trend analysis helps you make accurate projections and create tighter schedules.This saves you both time and money. 90010 90004 Concrete drying time is a major factor in the schedule of most construction projects and when you shorten that time, you save money. Following the tips in this article will help you do that. 90010 90154 90004 Jason has 20+ years ‘experience in sales and sales management in a spectrum of industries and has successfully launched a variety of products to the market, including the original Rapid RH® concrete moisture tests. He currently works with Wagner Meters as our Rapid RH® product sales manager.90010 .