weberfloor DPM can be applied on to concrete or cement based screed surfaces with a. This is done to maintain energy efficiency and prevent. 9% screeds been down since February. #5. 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. Country. Damp proof membranes (DPMs) can be used to help resolve damp issues which already exist or to avoid damp or moisture problems in the future. Im not quite sure where my DPC should be going. Warm water underfloor heating. Definition of terms See full list on ecotileflooring. uk ;. TB243. The polyethene slip membrane installed over the insulation must be overlapped and sealed to prevent loss of screed. blake floyds; 23 Jul 2009; Building; Replies 3 Views 5K. Customer asked me how did they stop rising damp before the Dpm sheet was used and it made me think ( that hurt ) . Brian shows how to correctly fit a Damp Proof Membrain - DPM in a new build houseLink to the T-Rex tape Website Http://bodgeitwithbri. I've read that you shouldn't install DPM under SPC flooring as it can affect how it clicks together 3. (DPM) between the concrete and screed. Small hole dug through 2" soft sandy concrete to reveal hardcore and soil. So he said to put the insulation on top of the slab. Whilst looking at the overall prices of each piece of work there's a couple of questions that have come up. Country. The purpose of DPM. Plastic DPM under slab everytime. 3 Oct 2004. "Your insurance company should be able to instruct property drying. I 've dug down and put 100mm of concrete down will liquid dpm to meet up with the existing dpm and 50mm screed ontop easy. Country. Bonded Screed Maximum Depth. hours for Ceramics. Mapeproof One Coat can be used with underfloor heating systems providing the system has been fully commissioned as per BS8203 2009, Section 3, 3. A standard sand/cement screed would need to be laid at a minimum depth of 65mm for a domestic property. The old adhesive should of been removed. If its not right. 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. not bonded to the base – typically where a DPM is placed under the screed. 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). In addition to the damp proof membrane (normally a 1200-gauge polythene sheet below the insulation), a 500-gauge polythene VCL. 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. Mine is below the concrete. 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. The DPM should: have sealed laps of at least 300mm wide. Country. The engineer (who is a bit belt and braces) recommended a block and beam floor supported by new foundations so as not to add extra load to the existing 1930s foundations. Mastic Asphalt – this is the earliest form of liquid DPM and is usually laid on the top of another membrane or a fibreglass surface. I really need to get the living room useable for my family and am hoping that a dpm under the engineered wood is possible. 29 per m², £42. All other sheet membranes can be used with unbonded toppings. The installation of the DPM is extremely important as this acts as a barrier to prevent damp rising up through the substrate, from the ground below. Will prim t be okay as primer on top of turbo? Thanks Pete Unless designed otherwise, the minimum specification for all partitions should be: sill and head plates 63mm x 38mm. 24 h After curing of screedSANS 10400, Part J Floors (which is the SABS “deemed to satisfy” regs) states: “Ventilation of the subfloor space in suspended ground floors shall be provided by means of openings spaced not more than 2,4. If it is the above type of screed and the latence hasn't been ground off, the screed won't be dry and will only start drying when the latence is taken. 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. Would that require two layers of DPM? For example: Level layer of hardcore; Layer of sand blinding; DPM; Concrete slab at a thickness of 3" inches; DPM (?) Jablite 70 floor insulation (75/100mm thickness) Vapour control layer ; Screed (1. In this article, I am going to give you the low-down on liquid DPM, where and how it is used and some of the things you need to consider. Screed & Insulation. Apply sand-blind base (this base should be level to within 5mm along any 3m straight edge). Pro-Screed Gold is moisture tolerant and can be used under and over DPM’s. This essentially means that the screed has been laid in direct contact against the bottom of the aluminium door frame. screed thickness. 21 Sep 2016. 50 /sqm. Out of the 7sqm of floor i guess about 1. . It is important to ensure that a proper seal is achieved around all services. rev 2023. Ball and Co. Why is a. 10 Sep 2021. The guidelines state that a damp proof membrane that is placed under the flooring should be around 1200 gauge and constructed of polyethene. Had a look at the pics and IMO no dpm under the subfloor. 2) 25mm - Celotex TB3000 Insulation Board. Mot1 Sand/hardcore sub base. VCLs prevent excess moisture entering a wall’s cavity, behind the insulation. also alot of the insulation manufacturers specify a 500/1000 gauge membrane between the insulation and the screed inkpad, Aug 6, 2009 #7. Using this latex based damp proof paint as a damp p. Hello, hoping someone can help. If DPM ok then. The idea is that you are to prevent any screed material from falling down any joints and coming into contact with the cold slab. However to get BC off your back you can use a epoxy DPM and sand scatter it before it sets. Said he'd provide a quote but didn't come back to me. #2. you need to dig up the old concrete then lay a couple inches of sharp sand. Warm water systems, such as those available at The Underfloor Heating Store, feature an array of pipes, laid just below the surface of your floor. 34. Hi I have fibreboard underlay in the instructions for the underlay it states if using this product on ground floor you should also use vapour barrier or damp proof membrane beneath the underlay. The screed manufacturer agrees that their screed can receive an epoxy DPM. ARDEX DPM 1 C may be used if; 1. 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. I am putting down a 22mm engineered oak floor so will use an underlay without a dpm. In both cases the surface on which the dpm is laid needs to be as smooth as possible. Currently, the central heating pipes and mains water pipes are all buried below the damp proof membrane, under the screed. A traditional sand and cement screed is normally a 1:4 or a 1:3. You are therefore at the edge of the joists capability. 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. Once the DPM is applied you need a laytex screed, so your adhesive and karndean stick to it. We converted our garage and building control are insisting I install a DPM over the screed (even though the DPM runs under the concrete raft foundation of the house). This is usually a simple 1200 gague polythene membrane and sometimes a more complex drainage membrane or liquid DPM. You are talking about a solid concrete floor which has to be on load bearing stable ground. British Standard (8204:1) says minimum 65mm for domestic floating. When we stick any floor down to the sub floor, solid or engineered, we insist on installing a liquid DPM unless the existing is guaranteed to be 100% in tact. We've just had our garage converted and our builders have laid a screed floor. water will be likely to collect between the DPM and the old floor. Beam and block floors may need a levelling screed or grouting to ensure base level. For bonded screeds, M-Bond Extra epoxy resin combined DPM and bonding agent may beToday, new solid floors are far more substantial, typically comprising 150mm of compacted hardcore, 50mm of sand, a polythene sheet DPM, 100mm of concrete, then around 100mm of insulation plus a 60mm screed — in total, more than 450mm thick. 17) DPM under slab. Can be used as a Damp Proof Membrane on sub-floors not under hydrostatic pressure. My work will be (in order of layers): 1) DPM 1000 gauge with joints taped with Polythene joint tape. Hi All, I'm purchasing a new build and want to put Amtico Spacia down throughout the downstairs. The DPM should extend up the external foundation walls to meet. ) • Floating (used to enable installation of thermal or impact sound insulation). Reinforcement to Suspended Floor SlabsClick and buy N-Virol Superseal Plus Damp Proofing DPM Paint which an be used for several applications including damp walls, floors and on basement walls. Installation systems for tiling and natural stone. Coverage: Approx 6 m at 3 mm thickness. BAL DPM is resistant to water, chemicals, grease and pollutants, and can be used internally or externally either as a DPM, primer, waterproofer or residual m. 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 the. Our self levelling compound, or floor screed, is available in a wide range of varieties for a multitude of floor installation applications. Pricing. do I still need a DPM under that insulation? it is internal and sitting on a structural slab that is wrapped in DPM externally. The basic screed construction for under floor heating systems generally follows the ‘floating’ screed construction, where a Damp Proof Membrane (DPM) and tacker insulation panels are laid over the concrete substrate before laying the heating elements of the under floor heating system. Effectively, a damp proof membrane (DPM) is used to create a barrier between a concrete (or screed) subfloor and a wood floor. 150mm PIR insulation. 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. Temporary protectionI had part of a 9" wall knocked down for a doorway. Damp proof membranes (DPM) A DPM should be a minimum thickness of 1200g polythene and linked to the DPC with a minimum 100mm overlap. The old floor tiles do contain a small amount of asbestos ( Marley tiles etc. Damp proof membranes (DPM) A DPM should be a minimum thickness of 1200g polythene and linked to the DPC with a minimum 100mm overlap. My query is regarding the floor insulation, damp proofing and screed. I was hoping to use a recycled content DPM. Yup so the plan is: Existing garage is concrete which is a 75mm lower than the current house level. Applying Damp Proof Membranes. pipes or cables for under floor heating should always be installed on top of the tanking membrane, not beneath it. 1314. ARDEX DPM 1 C may be used if; 1. 5 ratio of cement to sharp sand. This allows for the full 5kg or just half to be mixed at once depending on the area to be covered. DAMP PROOF MEMBRANE. 001 Ardex Australia 2015 Bulding regs would require 100mm insulation and 70mm reinforced screed for this. I want to level my workshop floor. do I still need a DPM under that insulation? it is internal and sitting on a structural slab that is wrapped in DPM externally. What should normally happen is the inner course should be removed to concrete slab level. High quality painting, plastering and drywalling tools. 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. SikaBond® Rapid DPM is a single part moisture curing polyurethane. 00 per roll. Mark El-Kadhi New Member. Our team of highly experienced technical experts are always on hand to provide the highest level of support and advice to our customers. 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”. 65mm Screed. Liquid DPM for Walls. So, as money's too tight to mention round here, I replaced the leaking door with a cheap UPVc one. 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. doors. The floor originally had a carpet laid on top of the tiles, when I lifted it nothing felt, looked or smelled damp. heating installations with cementious screeds provided a temperature of 27°C is not exceeded. Renovation property: £60 to £85 per square metre. 00. 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. Price: £4. As nod mentioned, your DPC will actually be the first layer of DPM you put down bef ore the insulation. then ducting should be provided to allow air through the solid floor and into the void under the existing house. Hi All come across this forum and would really appreciate some assistance. They can therefore be laid under the DPM (the DPM is still necessary to prevent. DPC and DPM are lapped together at this stage. Then once the screed is dry use a liquid DPM such as F-Ball Stopgap F77. Out of the 7sqm of floor i guess about 1. Slightly below floor level are two layers of polythene membrane with a layer of floor levelling screed to make up to floor level. Floor screed PIR cavity board Lay, level and compact the hardcore in layers (usually 150mm min / 250mm max). 19 Mar 2011. above the slab I am having a screed to cover the UFH pipes. £ 49. You'll also need to take the dpm up the walls as well. Non-structural floor screeds shall be adequate for the location and intended use, and provide a suitable background for floor finishes. Self levelling compound is often known as floor screed or floor levelling compound and is essential for creating an even floor surface in preparation for upper flooring layers. The basic screed construction for under floor heating systems generally follows the ‘floating’ screed construction, where a Damp Proof Membrane (DPM) and tacker insulation panels are laid over the. The dpm has added to the problem by removing any bonding capabilities within the floor screed. Be very careful by rushing. 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. Effectively, a damp proof membrane (DPM) is used to create a barrier between a concrete (or screed) subfloor and a wood floor. DPM sheets should be overlapped by at least 300mm. Ideal for use in shower areas where screeds are laid to falls incorporating a damp proof membrane. Checkatrade offers the following guide: Electric underfloor heating cost. Notch7. rogerk101 likes this. 5kg multi chamber bags. Maybe better to use a fibre based leveling compound instead, like Granfix Fibreflex 50 or similar. Capital Valley Plastics Ltd Damp-Proof Membrane Black 1200ga 25m x 4m (47163) (55) compare. 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. As a rough guide, laying conventional screed costs around £15/m2, increasing by around £5/m2 when delivered ready-mixed. 30811761. Fig. The total floor insulation cost will have two elements – the cost of materials and. The old adhesive should of been removed. Seems fine so far. user contributions licensed under CC BY-SA. or as a sandwich membrane in base concrete or between the base concrete and screed. 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. 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 screed manufacturer agrees that their screed can receive an epoxy DPM. Hull. For rafts, DPM and screed must be on top of raft and screed must be at least 65 mm thick. 17 May 2010. #7. 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. In this scenario, a rigid foam insulation is usual, and as you’d want the same U value in the roof, we need the same thickness of insulation. You also should have removed the vinyl tiles before priming and screeding. RFC Liquid Damp Proof Membrane (DPM) is a professional 2-component applied surface primer. New-build install: £120 to £135 per square metre. USES For priming, consolidating and sealing of: Absorbent and non-absorbent sub-floors, consolidat-ing weak cement screed and isolation of old adhesive residues. #3. Discussion in ' Builders' Talk ' started by Liz990, Feb 21, 2021 . Dig it all up (Its possibly up to 50mm thick) Then lay DPM/Visqueen sheets tanked up the walls and lay new concrete or use an epoxy liquid DPM tanked up the walls and lay a deep base screed. Issues to be taken into account include: installation. A Damp Proof Membrane or DPM is a waterproof barrier that’s introduced between your sub floor and your wood floor. C. Now we realise this cannot be done and are trying to get out of a fix. Try it free. (DPM) with joints well lapped and folded. Ideally there should be suitable insulation below the underfloor heating pipe to resist the heat going downwards. As you would expect, you need as much heat as possible to flow upwards and into the room. if there is insulation also under the screed i. #2. Am hoping for UFH in screed (supplied won't do 50mm, only 65mm). It is not. 22) Steel. 1: Fill the gaps with concrete and get an asphalt company to lay an asphalt screed over it to restore the DPM. 001 Ardex Australia 201550mm insulation would be better than nothing be it under screed or timber. DPM under block and beam. Cutting open would void dpm so should be avoided. 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. As a rule self levelling screeds need an active DPM at some point below them other wise they will likely de-bond due to damp and this could be the reason it seems to be lifting easily. #2. Greater thickness of screed may lead to a colder floor. g. Block and beam grout/slurry wetness. Misinformed on this as he had put a dpm under the chipboard. Pro-Screed Gold can be applied from depths of 2mm to 12mm in one application and with aggregate it can be applied up to 30mm thick. An expansion gap may be necessary around the edge of the floor finish in screed or. You will need to tear the lot up. royaloakcarpentry Senior Member. Ground-bearing concrete floor slabs should be protected against ground moisture by providing a continuous damp proof membrane (DPM). Was looking to do liquid DPM sandwich with fball 1200/F77/1200 (or NA/1cDPM/NA but that’s costing another 30% more. . 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. DPM sheets should be overlapped by at least 300mm. That about sums it up, but if your DPM is also serving as a radon barrier (even in a low risk area) the DPM should lap across the cavity (with a downstand) to seal the cavity from radon. Prime and reapply , then screed to level and tile. The screed will be only ~50 max (not yet dug any up). Jan 24, 2019. Then mix up the high performance stuff as that is fibred and can be taken to a feather edge. With the number of planning applications for basement extensions rising by 183% according to research by Halifax, tilers need to be. A flat duct could now be layed over concrete (150×50 mm) this would encroach into insulation but as building regs are 75mm on floor insulation only 25mm. Curing under polythene 12 hrs 12 hrs Drying time to receive finishes - from removal of curing polythene sheet 50mm thickness and 50% RH. Posted July 28, 2021. This barrier is intended to stop moisture passing from one to the other. This will allow the screed to. If I did my external one at the same height then the outside floor height would sit very low so presumably I can put the external one at the same level as. There is a small section along the chimney where. Still struggling with how to retrofit the DPM (on rough old solid concrete floor) and insulation etc Am not going to manage brilliant insulation as I failed to realise we couldn't take the DPM above the DPC ( at 150mm), even tho there is the head height. 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. – the UK’s leading manufacturer of flooring adhesives and floor preparation products for the contract flooring industry. concrete slab. g. Yes. Manchester • Member since 5 Jun 2015 • 64 jobs, 95% positive feedback. The mat will get glued down to the screeded UFH, and then the. This self leveling concrete’s use of latex. The floor make up is compaced hard core, 125mm concrete, dpm, 100mm insulation, 75mm concrete screed ( polished and heated). Kingspan GreenGuard is available in a range of compressive strengths starting at 300 kPa 10% compression. 4 Screed. DPM over a new underfloor heated screed, the heating system must be turned off 48 hours before application. If in the screed then no problem with this. Below are a few photos of the extension so far which show the dpm that’s under the slab coming up next to the opening. 21. Outside ground should be. Hi guys. Looking for best method to both level and damp proof the concrete, to then be covered with a thin layer of celotex, then engineered wood. 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. hallbeck, Jan 26, 2010 #5. 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. 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. Therfore putting foil faced boards under screed is a waste of time and is the principle reason kingspan make tissue faced boards. 20m2, 50mm = 0. 25 Apr 2010. 4. F. 4 Apr 2017. It needs: 100mm or more of well compacted type 1 MOT, sufficient sand to blind, DPM, insulation, screed. floating construction then a second "slip". fix battens to subfloor - I can't raise the floor height with battens on the screed, but I could lift and remove the 50mm screed layer, fix 50mm battens at 400mm centres direct to the concrete slab, and then boards fixed on top of the battens. Registered Office: 6 Acre Close, Rustington, West Sussex BN16 3PG. By definition, Relative Humidity (RH) is a measure of the amount of water vapour present in the atmosphere relative to the amount of water vapour it can hold at that given temperature. It originally had Marley tiles stuck down with bitumen 'glue', but many of them are missing and I will remove the rest. Find. Contractor wants to paint Sika Primer MD on top of the self leveling compound. C. The DPM is tied into the internal leaf of masonry. if your DPM were above the concrete, the uFH would be heating a large damp lump of concrete. If you don't allow the screed to dry properly, the moisture will be trapped within the screed potentially causing failure. If there was no dpm I would suggest a uniformal distribution across the whole floor. Below Floor Screed 1. Non-structural floor screeds shall be adequate for the location and intended use, and provide a suitable background for floor finishes. 5kN/m2. Types of Liquid DPM. Hi, I’m after some advice/suggestions regarding my floor…We’ve recently moved into a 60s house which has a screed floor, on top of a concrete base with no DPM. someone suggested removing the blocks on the inside along the width of the bifold and screeding all the way to the brick course. the cut. Insulation is laid on the concrete and covered with a screed. The surface should be of sufficient quality and. with the concrete but the insulation. To avoid such issues, it is therefore extremely important to make sure that the screeds are given sufficient time for drying. Also there is no DPM under the slab. Produced from Recycled Material. Modified anhydrite screeds for use with UFH can now be installed as little as 35 mm deep with a 15 mm pipe in a domestic application. Would a liquid dpm work,in past I had similar problem, I've just poured some liquid dpm in to the hole & help it with a trowel to find it's way under the concrete,seem to work as I never had damp issue when I moved indoor stop cock to new position at previous place & here when I laid new pipe under utilty floor after clay pipe failed, 10 years on, not. This seems to have been used in abundance before the original screed was put down. In addition to the damp proof membrane (normally a 1200-gauge polythene sheet below the insulation), a 500-gauge polythene VCL. Your builder or yourself should have laid dpm under the dpc course on top of the hardcore Base laid on soft building sand . Our expert team are ready to offer you the very best solution for waterproofing. It is usual practice to lay vent pipe under concrete and dpm. Screeds are covered by BS 8204, Screeds, bases and in-situ floorings, (2004). 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. Use screed on top of a concrete base to give your floor a level and smooth finish. The insulation level and fabric of the building should always be factored into an underfloor. Ideal for use where there is no functioning structural DPM (common in older properties). First, divide the floor up. Some houses in early 70s don't have a DPM as I've found out over the years. For traditional screed, the usual total will fall within the range £18. Then use the correct screed. If under the screed this is normally a polythene dpm so the screed is then an. DPM is usually below the concrete, then the insulation, then a polythene sheet to stop the insulation floating as the screed is poured. So the floor has been there for 70. Moisture in the base will impede the drying of the screed. 25W/m 2 K to meet with building regulations, even if you didn’t plan to. It's a complete lack of knowledge on your floorlayers part or possibly just a carpet fitter trying his luck. 8). Tramex reading at the time of vinyl removal was 3-4+. The guy doing it tried to compensate by using more adhesive and most of the wood has. Spoke to makers of UFH system. 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. 3. . I intend to consult BC but would like to educate myself before I speak with them Thanks in advance. When stripping the bathroom, the area under the bath tub was bare concrete, lower than the rest of the "black" floor throughout the property. I recently had a new boiler installed and new radiators fitted, and the plumber has cut the old copper. Then the lamiante has trapped this water in creating the sweat. 12 Sep 2015. Visqueen High Performance Damp Proof Membrane. Can be used as a Damp Proof. Changed mate!constructed as a separate concrete (Figure 2) or concrete masonry (Figure 3) perimeter foundation wall with the slab laid later. Developed to suppress residual construction moisture in cementitious subfloors including power floated concrete and sand/cement screeds. The DPM can be used as either below the slab application, directly below the flooring surface or in a sandwich construction, between base concrete and the screed. The specific liquid DPM system will depend on the type of substrate or screed. 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. com. 5mm = 2. Drybase Liquid-Applied DPM should be used in situations where the final surface is going to be covered. It would have taken a lot of screed to make up the level - about 36 bags. Brian shows how to correctly fit a Damp Proof Membrain - DPM in a new build houseLink to the T-Rex tape Website Http://bodgeitwithbri. Ok so I have drawn the attached image. 2: Fill the gaps with concrete, lay a DPM over it, insulation, then a concrete / fibre screed. This will give calculated u-value of 0. . 75m2 at 3mm, 1. 13) Polypropylene. Then use the correct screed. New-build install: £50 to £75 per square metre. When stripping the bathroom, the area under the bath tub was bare concrete, lower than the rest of the "black" floor throughout the property. I could put the dpm under the concrete which would be as effective. The 'vapour barrier' attached to your underlay will only protect your floor from a slab reading 75% RH or less. You should use them to protect all final floor finishes. 74 inc. This should be laid on a bedding material such as screed which doesn’t damage the sheet and has fully sealed joints. 99 Inc Vat. So latex one its more likely the addy will be affected. Country. studs 63mm x 38mm at maximum 600mm centres.