. It is good practice to either fit another DPM or tape the insulation joints, when adding a screed on top of inso'. Resin and cementitious floor finishes combining performance and design. Contact Us. com. Our self levelling compound, or floor screed, is available in a wide range of varieties for a multitude of floor installation applications. Types of Liquid DPM. This should be laid on a bedding material such as screed which doesn’t damage the sheet and has fully sealed joints. . 20m2, 50mm = 0. No this is designed to be used under floor screeds, tiles, render or plaster. I would also gripfill under the plate to supplement the fixings if it were screed. #5. now what i know of screeding is very little but i can do a good job i have used in the past chicken wire under floor insulation, slurry coats on concrete etc but the guy who wants the job doing is going on about a barrier around. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. How to Damp proof a floor and walls using synthaproof as a damp proof membrane is shown in this tutorial. Thanks for reading. The liquid membrane forms a strong seal and makes a permeable layer to enable moisture to evaporate off. #1. The surface should be of sufficient quality and. dthobhani; 18 Mar 2011; Floors, Stairs and Lofts; Replies 2 Views 1K. The screed manufacturer agrees that their screed can receive an epoxy DPM. Hi All come across this forum and would really appreciate some assistance. (This is assuming its a slab insulation. 001 Ardex Australia 201550mm insulation would be better than nothing be it under screed or timber. The vinyl that was laid bubbled up, so contractor removed it. . A damp proof membrane (DPM) is used to create a barrier between a concrete (or screed) subfloor and the floor covering that is laid on top such as wood, ceramic or quartz tiles, laminate or carpet. Apply sand-blind base (this base should be level to within 5mm along any 3m straight edge). above the slab I am having a screed to cover the UFH pipes. Guidance on how to install insulation between a floor screed with Kingspan Kooltherm K103 Floorboard. Put an upstand of 25mm celotex around the perimeter of the room and a dpm under the concrete lapped up the walls, being higher than the dpc won’t matter Jimmycloutnail, Jan 23, 2019 #4. As you are always relying on the subfloor surface strength you are always at risk if there is no sheet DPM under the floor as it will be under pressure. We used the Ultra Floor system, Ultra DPM-it,. If the applied DPM is still very tacky, this1. Unbonded screeds are used either to install a damp proof membrane (dpm) between the base slab and the screed or where the base slab surface is unsuitable for a bonded screed due to problems such. Top. BONDED VERSUS UNBONDED SCREEDS Bonded topping screed installations are the most common as this allows the minimum thickness (15mm) to be applied thus limiting the weight load on the structure. £20 per m2. Walkable in 6 hours. POLYTHENE DPM & VAPOUR BARRIERS. The Epoxy DPM 5kg is supplied in two 2. If applying a screed to Drybase® Liquid-Applied DPM, the second coat can be used as a primer if the screed is applied while the second coat is still tacky. The heating must be switched off at least 48 hours before and after application Bostik Screedmaster One Coat DPM and Bostik Screedmaster One Coat Accelerator are both solvent free products and are suitable for use in all project workHow-to video with step-by-step instruction on how to apply liquid damp proofing, priming and then self leveling. 8 Can you put DPM under. If DPM ok then. This will give calculated u-value of 0. Curing Under Polythene 12 hrs 12 hrs Drying Time To Receive Finishes - from removal of curing polythene sheet 50mm thickness and 50% RH. For technical support please call. Cement screed. Find. I've dug down and exposed part of the DPM sheet under the slab so I'm happy using trade plan, turbo then renovation screed. Suitable for most construction damp proofing requirements. The subfloor. e. An ARDEX Damp Proof Membrane will protect the floorcovering. The advice of a structural engineer should be sought for any exceptional point loads in the design of the floor. This allows for the full 5kg or just half to be mixed at once depending on the area to be covered. 1 tonnes per m²), which is suitable under a 75mm screed in normal domestic situations. If you're laying Karndean over existing flooring, be sure it is properly prepared. They can be used under resin screed finishes and are applied in thinner sections than standard cement screeds. The surface should be of sufficient quality and. The only way to tell properly, is to carry out a proper test. 5mt x 4mt rolls | £ 56. Our Epoxy DPM can be used on concrete floors and fine concrete screeds, of not less than 50mm thick in the case of un-bonded screeds. The screed layer is damaged by damp, and is easily disturbed/crumbled. 4 so you have around 1. It is much easier to work on sections of the floor than try to achieve an even finish across the whole floor in one go. This self leveling concrete’s use of latex. The polythene damp proof membrane (DPM) – generally a 1200 gauge- can now be rolled out into place ensuring the perimeter abutments are adequately covered. Liquid DPMs gave the best protection but were more expensive. A DPM should be impermeable to water in liquid or vapour form and should be tough enough to withstand possible damage during laying of screeds, concretes or floor finishes. 1, your new concrete will need drying time, approx 1 month for every inch, then a DPM is required. Refer to manufacturer’s guidelines. The old adhesive should of been removed. Unless there is an easy way. Hi, I have an area of approx 6m by 3m on a ground floor extension which is block and beam construction, that I now need to insulate and screed to finished floor height. Can anyone advise me if this needs to be completely dried out before put the screed down? I have exposed part of the slab by removing th insulation and peeling back the upper dpm and this has slowly drie over the week but the dpm is keeping the wet in where its stil. What is DPM under screed? Damp-proof membrane (often called DPM) is used in construction to prevent moisture from entering the building, usually through capillary action. There is a concrete slab in place with a DPM underneath. Do you need DPM under screed? What DPM is Required? If the hygrometer reading comes back above 75% relative. In these cases the insulation goes on top of the slab. For bonded screeds, M-Bond Extra epoxy resin combinedWhen laying self-levelling screed, the thickness varies from product to product, however as a general guideline please find the depths below: Minimum depths are usually 2-3mm, however there are some products that can go down to “featheredge”. Onto the concrete. com. Was looking to do liquid DPM sandwich with fball 1200/F77/1200 (or NA/1cDPM/NA but that’s costing another 30% more. 5m height allowed under permitted development as possible. They can therefore be laid under the DPM (the DPM is still necessary to prevent. PermaSEAL Liquid DPM can also be applied to concrete floors below screeds. Guarantees the early laying of all floorcoverings. 28. 21. Am hoping for UFH in screed (supplied won't do 50mm, only 65mm). Floor under carpet marked with chalk for wet areas. Easy Handling & Installation. Stack Exchange Network. 99 Inc Vat. 65mm Screed. you then have a continuous damp couse not inportant if concrete above dpc level. SikaBond® Rapid DPM is a single part moisture curing polyurethane. TB243. Ok so I have drawn the attached image. Small hole dug through 2" soft sandy concrete to reveal hardcore and soil. The Epoxy DPM 5kg is supplied in two 2. Or have you asked them can you install Surface DPM on a Wet subfloor that does still have a DPM under it? Don't confuse the TWO. UFH Pipwork. Yes run the dpm up the wall to connect wall dpc with floor dpm. How to screed by hand step-by-step with our stars Luke and Lee who are at the top of their game and Luke is only 18 years old, very impressive. They left the bitumen glue on the floor (apparently, this is often ground off before laying screed), and applied PVA to seal the bitumen, which also contains small amounts of asbestos. Country. Spoke to makers of UFH system. Material. Unfortunately soon after it was laid it started crumbling and holes were appearing in places, as electricians and plasters came in to do their work and walked all over it, they did put black sns plastic sheeting down to protect it though. 24 Jul 2009. A typical beam and block application would have beam and block 100mm depth, insulation between 150-300mm and screed 65-75, a total floor depth of between 325-475 which could require as many as three extra rows of brickwork. Apply ARDEX DPM 1 C to protect the floorcovering installation from residual construction moisture and ground bearing moisture. m10 cement based levelling and wearing screeds 160 m12 resin flooring 163 m13 calcium sulfate based screeds 165 m20a plastered coatings 166 m20b rendered and roughcast coatings 169 m21 insulation with rendered finish 172 m40 stone, quarry and ceramic tiling or mosaic 173 m42 wood block composition block and mosaic parquet flooring 1763. Guidance on how to install insulation between a floor screed with Kingspan Kooltherm K103 Floorboard. Effectively a thick plastic sheet, a damp proof membrane (DPM) is used to create a barrier between a concrete (or screed) subfloor and a wood floor. Registered Office: 6 Acre Close, Rustington, West Sussex BN16 3PG. Ground-bearing concrete floor slabs should be protected against ground moisture by providing a continuous damp proof membrane (DPM). Thanks for the reply. This is why first choice is always strip footings. FlexiDry said: Yes laying the screed direct onto insulation is standard practise for a floating floor. Flexible - easy to detail and install on site. Lay and level the concrete slab, allowing sufficient time to dry out, as per BS 8203. I was with Mapei last week inspecting a failed DPM that had been laid on a subfloor with no DPM under it. The DPM (Damp Proof Membrane) is laid under the insulation on top of a soft blinding to ensure it is not punctured. When stripping the bathroom, the area under the bath tub was bare concrete, lower than the rest of the "black" floor throughout the property. #7. #3. 5kg multi chamber bags. For unbonded and floating screeds, a DPM may be specified between the base slab and the screed. It still might not have a DPM under the floor. Installing floor insulation boards above the concrete slab and below the floor screed is an effective insulation method particularly for underfloor heating systems where the underfloor heating pipes are contained within the floor screed. Small domestic areas that are going to have carpet, wood or synthetic floors as the final surface are ideal to use in conjunction with. The idea is that you are to prevent any screed material from falling down any joints and coming into contact with the cold slab. A traditional sand and cement screed is normally a 1:4 or a 1:3. DPM, Celotex, 1000 gauge poly, 100-150mm concrete with or without reinforcement, 50-80mm screed. New-build install: £120 to £135 per square metre. Is this okay? Or does this present a real risk of corrosion of the frame in the future?that's rising damp mate, need to dig up subfloor new concrete base, dpm leave 30 days then screed and surface membrane that should help fix the problem. blake floyds; 23 Jul 2009; Building; Replies 3 Views 5K. In order to prevent damp rising through the concrete floor and causing issues, a DPM should be used under all final floor types including wood flooring, laminate, vinyl and floor tiles. Other benefits. Ideal for use in shower areas where screeds are laid to falls incorporating a damp proof membrane. indd 2 08/08/2016 16:50:21DPM underneath and a plastic sheet on top to stop the screed getting between the insulation panels. The asphalt screed provides a membrane to the surface of the concrete floor preventing moisture within the constructional slab causing decay to the floor coverings. . Damp Proof Membranes. Why is a. DPM sheets should be overlapped by at least 300mm. Yes it is a small breach on regs but would be up to building control to decide. -markie-, Feb 10, 2020. Suitable for use with underfloor heating and for encapsulating electric cable undertile heating systems. #5. Unbonded Sand and Cement Screed Minimum Thicknesshelppppppppppppppppppppppppp just had to quote for screed flooring. If under the screed this is normally a polythene dpm so the screed is then an unbonded screed, whereas if the dpm is on top of the screed an epoxy-type dpm is used. DPM, Celotex, 1000 gauge poly, 100-150mm concrete with or without reinforcement, 50-80mm screed. The installation of a liquid damp proof membrane is a vital stage in the construction process, for both new builds and refurbishment work where a structural DPM may be missing or damaged, or where residual construction moisture is present in the floor. Coverage: Approx 6 m at 3 mm thickness. An important benefit of Jablite Thermal Floor Systems are the speed of installation. Misinformed on this as he had put a dpm under the chipboard. LAY DAMP PROOF MEMBRANE. It offers thermal conductivities as low as 0. Hoping the power of the Screwfix forum can help with a totally baffling problem we are having with our new extension. 1 Feb 2010. The maximum depth you would use a smoothing compound would generally be around out 10mm, you can add aggregates, to bulk up the screed going up to 30, 40, 50+mm. DPC and DPM are lapped together at this stage. This barrier is intended to stop moisture passing from one to the other. As a rough guide, laying conventional screed costs around £15/m2, increasing by around £5/m2 when delivered ready-mixed. The plan was to lay American Black Walnut but the hallway floor was not level. This DPM is a ‘thick’ plastic sheet mostly 1000 – 1200 gauge polythene material. A hydronic setup is connected to your central heating system, powered by a boiler or some form of renewable tech (eg a heat pump). Because we were laying Karndean Flooring to a new extension we needed to check the % RH(relative humidity) of the concrete with a hygrometer. New-build install: £50 to £75 per square metre. 14) Screed. 3) 50mm - Screed with Concrete Fibres, on top of the insulation boards. weberfloor DPM can be applied on to concrete or cement based screed surfaces with a. Care must be taken to a) ensure there are no holes or tears in the sheet that could allow. Tape is a non starter. Our Epoxy DPM can be used on concrete floors and fine concrete screeds, of not less than 50mm thick in the case of un-bonded screeds. Can you put DPM over screed? Liquid DPM is a system that is used over a base floor. Like a lot of houses of that age, the ground floor is bitumen/asphalt over a concrete screed. Out of the 7sqm of floor i guess about 1. weberfloor flex is a self-smoothing floor levelling compound — often incorrectly referred to as a self levelling screed or self levelling floor compound — which can be tiled onto and is an easy screed for applying onto floor substrates subject to some movement, such as wood or underfloor heating. Curing Under Polythene 12 h 12 h Isocrete K-Screed (Heavy Duty) COMPRESSIVE STRENGTH (28 DAYS) BS EN 13892-2 >30 N/mm2 BRE TEST CATEGORY BS 8204-1 Category A. Energy Efficiency: Concrete floors generally possesses lofty thermal mass & this may be. 8 Oct 2015 #4 So you have a concrete slab laid on a DPM, and later a 65mm sand & cement screed laid on the Extn. Two coats will provide protection up to a maximum hygrometer reading of 95% RH. below this liquid screed I am adding 50mm EPS100 to build up the depth (which reduces the thickness of the screed) and also to fix the UFH pipes to. The dpm needs to be clean and dry. 21m2 1. Floor board overlaps new screed by 50mm so is supported by new screed on inside edge. Temporary protectionI had part of a 9" wall knocked down for a doorway. Renovation property: £60 to £85 per square metre. 21 Sep 2016. 15 Feb 2015. DPMs on top of the slab, i. steve have you checked the level of all of the concrete floor. AFAIK - PIR insulation boards need have a DPM under them to protect the board. 150mm PIR insulation. (See FeRFA Guidance Note No. e. Scaffold boards should be used for barrowing and tipping concrete and screed and a light mesh of chicken wire can be used over separating layers or dpms over insulation under screeds as added protection. Screed on top of slab is cracked/crumply/blown so that’s come off and now down to the concrete. The company keeps abreast of market developments by. The dpm has added to the problem by removing any bonding capabilities within the floor screed. Country. BONDED VERSUS UNBONDED SCREEDS Bonded topping screed installations are the most common as this allows the minimum thickness (15mm) to be applied thus limiting the weight load on the structure. Looking for a FLAT membrane as I am told the creases you get when you unfold 4m wide DPM / polythene from a 1m roll can cause cracks (plus its a real pain to lay). Using pin m/m's on a concrete or s&c screed floor needs experience - more important is what is the composition of the slab or the in-situ screed and if there is an actual DPM below the floor. Polycote DPM Primer is a superb twin pack high-performance epoxy coating that. This process is not 100% foolproof and so during screeding an extra pair of hands is useful to tuck the materials together until the weight of. SikaBond® Rapid DPM is a single part moisture curing polyurethane. The 40mm between the joists is about 0. 19 Mar 2011. 2 Feb 2010. 6. They can therefore be laid under the DPM (the DPM is still necessary to prevent. 9. You could asphalt but it will eventually fail one day and you'll need to do it again although it is the cheaper immediate option. g. Information ARDEX DPM 1 C. Then use the correct screed. The surface should be of sufficient quality and. Right based on those joist spacings and dimensions the joists should easily accept 1. The bitumen adhesive also contained the same asbestos fibres. The position would vary in accordance with proposed methods of construction. Any advance on laying 75mm kingspan directly on existing screed with DPM beneath, then laying 18mm T&G moisture resistant chipboard. com. 8mm2 at 6mm 1. For an excellent balance of. For bonded screeds,4 weeks will depend on the depth - keep the screed as thin as possible - with wet UFH normally 50mm - any more will delay the drying time. The clips only pierce the thinner layer above the insulation, which is only really there to ensure an unbonded concrete/screed above. 17) DPM under slab. When incorporating under floor heating: Screeds should be isolated at all edges, abutments and columns to allow for movement due to thermal loadings; The manufacturers’ guidance for both the floor screed and the tiling must be followed to determine the minimum thickness of edge strip required to allow for expansion. Property is mid 1960s, solid ground floor. Telephone: 0800 270 7837. The idea is that you are to prevent any screed material from falling down any joints and coming into contact with the cold slab. Traditional screeds. 4. USES For priming, consolidating and sealing of: Absorbent and non-absorbent sub-floors, consolidat-ing weak cement screed and isolation of old adhesive residues. I'm not saying this is the best thing to use. Let the slab dry first. Ball and Co. CSC screeding was very efficient that they screeded our floor in under 4 hours (around 91sqm) with the help of the Mixamate. Mobile Sales: 07920 715745. 34 dpm under insulation and screed. Go for the application of a surface DPM; The third option is however quite expensive, and could turn out to be more expensive than the screed itself. For this, a metal mesh standing with plastic pillars ( (feet) will be laid before the concrete is. New-build install: £50 to £75 per square metre. If you are installing where existing floors have been removed, check that there are no traces of previous adhesive residue. To add to this, when we bought the house about 6 months ago the existing felt roof (on the extension) had a gaping hole that was letting rain water. We’d recommend using timber battens to act as a guide – apply a small amount of screed to the flooring to lay the battens on, and lay the battens in strips across the floor. Use polyethylene sheeting to create a waterproof membrane to ensure that there is no leakage of the screed when it is pumped in wet. 100mm c35 concrete with mesh. #1. T ·Öà 4 ·Öò 8 ·Ñ• 2, Jun 15, 2007. Some houses in early 70s don't have a DPM as I've found out over the years. screed (with UFH) 75mm. Give it a good wipe with a damp cloth and let it dry before you start. hence my suggestion that this dpc should lap up and over to join the dpm (under the insulation and screed), which in turn laps with a second higher dpc beneath. Like x 2; Agree x 2; List (You. ← Installation of rigid floor insulation on ground floor concrete substrates to receive screed. Water is added to ensure a thorough mix and to aid workability. 13) Polypropylene. Slightly below floor level are two layers of polythene membrane with a layer of floor levelling screed to make up to floor level. Consideration should be given to applying the DPM to the top of the slab, as the installation and moisture sensitive internal finishes are then protected from any residual moisture in the concrete. I could put the dpm under the concrete which would be as effective. The floor make up is compaced hard core, 125mm concrete, dpm, 100mm insulation, 75mm concrete screed ( polished and heated). weberfloor DPM is a two-component epoxy based chemical damp proof membrane that is capable of being applied in one coat, dependent upon the condition of the substrate and quality of workmanship to ensure full coverage is achieved at the required thickness. The DPM should: have sealed laps of at least 300mm wide. 250mu (1000G) Black Polythene Damp Proof Membrane (DPM) 4m x 25m (100m2/Roll) URN: 5004075. When applied on top of screed, it needs to have a further coating to protect it from damage such as laminate, tiles, vinyl, wood and carpets. ) • Floating (used to enable installation of thermal or impact sound insulation). or email. The guidelines state that a damp proof membrane that is placed under the flooring should be around 1200 gauge and constructed of polyethene. C. Brief background: After buying a 1960s semi in south Birmingham house last year, and spending the summer managing (a) complete rewire; (b) installation of satellite and Ethernet wiring to all rooms; (c) plastering to make good chasing from (a). I am happy to employ gs guy to do pipe and install boiler but don't want to be calling the guy several times months appart, hence the attempt to make. Applying Damp Proof Membranes. The purpose of DPM. Relative Humidity: The moisture content or relative humidity of the atmosphere plays is a major factor that affects the drying time of the screed. Temporary protection should be given As proven in this Celotex Floor Insulation Guide, Celotex insulation is a versatile and effective flooring insulant. Visqueen EcoMembrane DPM. floating construction then a second "slip". Cushion Ultra Silver Wood 10m² Underlay: The best laminate underlay for damp protection. Vac up any loose sand once it's set and then tile. The extension is yanked and the architect has spec'd Marley Dampseal for the dpm which will sit under 60mm of Kingspan and 75 mm of screed. Bostik Screedmaster Rapid DPM is a ready for use; one part, water-based damp proof membrane. HYDRONIC UNDERFLOOR HEATING A CONCISE GUIDE FOR ARCHITECTS & SPECIFIERS ON PLANNING UNDERFLOOR HEATING SYSTEMS Introduction This guide is intended as a basic guide to the fundamentals of hydronic underfloor heating to assist specifiers to incorporate underfloor heating in their design. by sound of it you could latex that floor 3x with the amount of screed you intend buying and you can't prime under a dpm or dpm over a water based screed. VAT £ 0. 27 Dec 2020. It is advisable to have a minimum of 100mm insulation covered with 60-80mm screed. hot bitumen, or cold bitumen in solution. Pumped anhydrite floor screeds are not much dearer than ready-mix sand/cement, costing around £25/m3 (laid. California Country. 4. i'n not farmiliar with wickes dpm and the primer used for professional (if you like) screeds is neoprene. 4 Screed. Pumped Anhydrite Screeds. The work falls under building regs part L and you need minimum 70mm PIR insulation. The DPM is tied into the internal leaf of masonry. Country. This allows for the full 5kg or just half to be mixed at once depending on the area to be covered. We have a few options: 1. However I'm pretty sure there is no damp proof membrane (or course?) as our water source, a large well, is under the floor and a couple of years ago it flooded into the dining room. take account of possible differential movement. Our expert team are ready to offer you the very best solution for waterproofing. Mot1 Sand/hardcore sub base. DPM (1200 gauge visqueen) Old Concrete Slab. As a rough guide, laying a conventional sand/cement screed costs around £15/m2, increasing by around £5/m2 when delivered ready-mixed. My query is regarding the floor insulation, damp proofing and screed. "Turn off electricity and gas only if it’s safe to do so," he said. Instead of a membrane, use a foam underlayment material which will keep the wood from touching the screed directly (avoiding any moisture transfer) but which will also allow the screed to breathe and thus dry over time. Country. 4) at a thickness of 3" inches The guidelines state that a damp proof membrane that is placed under the flooring should be around 1200 gauge and constructed of polyethene. Our Liquid DPM can be used on walls under a render to create a flexible waterproof layer. With a laser. There will be a damp-proof membrane under the insulation and possibly a second membrane on top, depending on the type of screed. If in the screed then no problem with this. This is done to maintain energy efficiency and prevent. You can lay a fast track DPM (damp proof membrane) if your new concrete has had 2/3 weeks drying time. Insulation Below A Floor Screed. Deleted member 25896, Feb 2, 2021 #5. 18) Bricks. #2. you can then lay your celotex or similar then concrete then screed or dpm concrete insulation screed . someone suggested removing the blocks on the inside along the width of the bifold and screeding all the way to the brick course. 12 Sep 2015. Now we realise this cannot be done and are trying to get out of a fix. 0. Screed & Insulation. Insulation is a crucial consideration for UFH. Pumped anhydrite floor screeds are not much dearer than ready-mix sand/cement, costing around £25/m3 (laid to a 50mm depth). applications are suitable for bonded topping screeds. xednim, Apr 6, 2019. We have our sub concrete floor in, and there will be a 1200g dpm, then 100mm insulation, then another dpm and finally 65-70mm screed. The reasoning behind the 'sub-base:bedding' school of thought is that the membrane prevents the bedding from trickling down or being washed into any voids within the sub-base material, while the 'sub-grade:sub-base' orthodoxy, in which I include myself, maintains that keeping the sub-base material from mixing with the sub-grade, and reducing or. the screeder I use sets up a laser level and sets out his screed to that, the finish is always really good, much better than using long levels to transfer from section to section. It has to breath to survive. 5sqm has blown. 5m2 at 1mm thickness 1. Step 3: Lay the watertight membrane. Beam and block floors may need a levelling screed or grouting to ensure base level. With the power of hindsight I would have made the slab the same size as the structure so the bricks were flush with the edge then left enough DPM to run. The water got under the DPM and wet the slab and blinding layer. Cement screed is the most commonly installed type of screed and is suitable for both interior and exterior surfaces. You will need to tear the lot up. Can be used over underfloor heating. Mark El-Kadhi New Member. High quality painting, plastering and drywalling tools. Then use the correct screed. Also, even with 80mm screed directly over Celotex the sab can feel a bit "hollow". JB Flooring Well-Known Member. 0113 2455450 sales@rawlinspaints. When this is down I will then lay more sand or light concrete mix up to the level of the old screed or just below, then let this dry and then apply about 3 coats of bitumin floor paint. The following week, I got high moisture readings (90% plus) in several places on the concrete flooring, from a hygrohood I borrowed from a local flooring company. 23 Dec 2020. It's a complete lack of knowledge on your floorlayers part or possibly just a carpet fitter trying his luck. 5. do I still need a DPM under that insulation? it is internal and sitting on a structural slab that is wrapped in DPM externally. Under Floor Heating; Screed Care; Testing; Tips; Blog; Contact; A Practical Guide to Screed Testing: What Do the Experts Say? Download. first of all check your existing floor is perfectly level, if not then forget the freeflowing screed as it will not level up with the existing floor. Ideally with a screed pump. framing joints secured with not less than 2 nails per joint. The Epoxy DPM 5kg is supplied in two 2. As with the Kooltherm installation, start by ensuring a clean and level surface. Use 1000 gauge or thicker – ideal for this is the polyethylene use for the DPM under your concrete subfloor. It may well require the re cement to be removed, a liquid dmp used with dry sharp sand thrown on it before it dries, and then use a flexible self levelling screed. Floor screed PIR cavity board Lay, level and compact the hardcore in layers (usually 150mm min / 250mm max). 3k. - Polythene membrane (DPM) - Insulation (rigid board type) - Concrete slab min. DPM sheets should be overlapped by at least 300mm. Posted July 28, 2021.