. 3. Insulation will then go on top and the screed layer would go over the whole lot. 9% screeds been down since February. Also, even with 80mm screed directly over Celotex the sab can feel a bit "hollow". This essentially means that the screed has been laid in direct contact against the bottom of the aluminium door frame. Step 3: Lay the watertight membrane. A floor screed is usually a cementitious material made from a 1:3 or 1:4. A suitable gauge damp proof membrane (DPM) and thermal insulation must be provided. The difficulty is getting the underneath concrete to have a flat surface at exactly the right level. Then use the correct screed. Coverage: Approx 6 m at 3 mm thickness. 3 Oct 2004. The insulation level and fabric of the building should always be factored into an underfloor. Uses/Subfloors:If you have under floor heating, you can use it to dry the screed 7 days after installation and the additional depth, (up to 65mm), becomes less important, But you’re still wasting money on screed you don’t need. 5kg multi chamber bags. Replacing over half of your floor will mean you’ll have to insulate to at least 0. That seems to be the recommended practice but I'm not sure how many bother with the one on top. To avoid such issues, it is therefore extremely important to make sure that the screeds are given sufficient time for drying. . When I origianlly pulled it up it was damp under the bitumen screed/dpm around some cracks in the slab (guess trapped moisutre was trying to escape there), it dried in about 10-15 minuntes and has been done dry and. 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. (This is assuming its a slab insulation. carpet, tiles etc. This will leave bitumen (ironically) glue residue behind which is a problem to remove I believe - and must be completely gone. I'd like to change our tiled dining room room floor to a carpeted floor with underfloor heating. 3. Misinformed on this as he had put a dpm under the chipboard. Kingspan GreenGuard is available in a range of compressive strengths starting at 300 kPa 10% compression. 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. #1. 30 Jun 2023. 50 /sqm. studs 63mm x 38mm at maximum 600mm centres. Vac up any loose sand once it's set and then tile. We could scrape up the tiles and start again. TB243. If the applied DPM is still very tacky, this1. The mat will get glued down to the screeded UFH, and then the. Also there is no DPM under the slab. For under screed use: Must have from ground up: dpm (under subfloor in this case), insulation, plastic vapour check, sand-cement screed or fibre-concrete. Right based on those joist spacings and dimensions the joists should easily accept 1. 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) and (b); (d. There will be a DPM under the slab and up the edges already. This should be laid on a bedding material such as screed which doesn’t damage the sheet and has fully sealed joints. Below Floor Screed 1. VCLs prevent excess moisture entering a wall’s cavity, behind the insulation. with the concrete but the insulation. This can only normally be guaranteed if its an new build or extension and most houses have been sold, inherited etc. 45sqm to supply and fit. 12 Sep 2015. the advice by these two posters is absolutely incorrect, if your RH% is above 75% you absolutely need a surface dpm and dual screed the test takes 72 hours to take though, depending on size the price you were quoted is reasonable (surprisingly from. Discussion in ' Builders' Talk ' started by Liz990, Feb 21, 2021 . Country. The polythene damp proof membrane (DPM) – generally a 1200 gauge- can now be rolled out into place ensuring the perimeter abutments are adequately covered. O and the Answer to Mapei and Uzin is no. 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. (DPM) between the concrete and screed. A hydronic setup is connected to your central heating system, powered by a boiler or some form of renewable tech (eg a heat pump). Insulation would be a good idea, but it also may not be a bad idea to knock the whole thing down and start again if the walls are only 4", the floor is rough, and the roof probably leaks too. It is black/blue in colour and comes in conveniently multi-folded rolls. flooringman Well-Known Member. 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. 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. Curing under polythene 12 hrs 12 hrs Drying time to receive finishes - from removal of curing polythene sheet 50mm thickness and 50% RH. It should be waterproof to prevent any rising damp getting through. do I still need a DPM under that insulation? it is internal and sitting on a structural slab that is wrapped in DPM externally. 5 ratio of cement to sharp sand. It is advisable to incorporate a light mesh within the raft for reinforcement. 3k. We have a few options: 1. But too much water will extend the drying time and. Hull. As nod mentioned, your DPC will actually be the first layer of DPM you put down bef ore the insulation. (See FeRFA Guidance Note No. Out of the 7sqm of floor i guess about 1. It originally had Marley tiles stuck down with bitumen 'glue', but many of them are missing and I will remove the rest. Alan Jackson - Commercial Manager UK and Ireland - Gypsol. How to Damp proof a floor and walls using synthaproof as a damp proof membrane is shown in this tutorial. This means of course I can't get a DPM under the slab; is it ok to put the DPM over the concrete slab, and then put down 50mm insulation and then 100mm screed? Ed209 , May 1, 2020 #1Assuming that the damp proof membrane (dpm) under the concrete has failed in areas then yes you possibly would get the odd patch of dampness showing in the floor. enquiries@visqueen. Then once the screed is dry use a liquid DPM such as F-Ball Stopgap F77. AN INTRODUCTION TO. Depending on the use of the building, the slab can then be finished ready for use, or receive a screed suitable for a floor finish. It also looks like there could be polystyrene under the screed, this will be a barrier to damp coming from the ground. Once set, you can then apply your screed flooring to the DPM base. Once set, you can then apply your screed flooring to the DPM. "Remove water with pumps or buckets and contact your insurance company straight away. £51. Should I lap DPM under or over Dpc then celotex, then another DPM lapped up the wall with 25mm up stands. To remove the screed in order to relay a DPM is, in most cases, completely unrealistic and actually completely unnecessary. #2. For unbonded and floating screeds, a DPM may be specified between the base slab and the screed. I've read that you shouldn't install DPM under SPC flooring as it can affect how it clicks together 3. you then have a continuous damp couse not inportant if concrete above dpc level. g. 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. As a waterproofer, BAL DPM is an easy two-coat system when used with BAL Self-Adhesives Butyl Tape in corners and junctions. The main issue you need to remember about the DPC at the external walls is to have an upstand on the inner leaf and slope down to the other leaf. What’s the difference between a DPC and DPM? The DPM dries to form a permeable membrane that allows moisture to evaporate off in a controlled way. 74 inc. 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. Cushion Ultra Silver Wood 10m² Underlay: The best laminate underlay for damp protection. Side extension refurb: old concrete slab is uneven with a line of about 10mm difference in heights down middle, and dpm under screed is visibly not 100%, with a few gaps. Traditional screeds. Flexible - easy to detail and install on site. I want to level my workshop floor. In these cases the insulation goes on top of the slab. You can lay a fast track DPM (damp proof membrane) if your new concrete has had 2/3 weeks drying time. Yes. Insulate under the floor using the crawl space underneath. This seems to have been used in abundance before the original screed was put down. Then use the correct screed. Celotex PIR’s closed-cell, moisture-resistant composition helps to prevent water ingress. Liquid DPM for Walls. The floor originally had a carpet laid on top of the tiles, when I lifted it nothing felt, looked or smelled damp. As for the rest of the bungalow, I noted that there is DPM under most the sole plates of the original stud walls around the bathroom, but it's. Relative Humidity: The moisture content or relative humidity of the atmosphere plays is a major factor that affects the drying time of the screed. Depends where the UFH pipes are. If DPM ok then. Ask the mods to move your thread to Flooring forum and see: dazlight Fri 29 aug 2020 for a specific response to a difficult surface. ← Installation of rigid floor insulation on ground floor concrete substrates to receive screed. Damp proof membranes can be used to help resolve damp issues. BBA certified - third party accreditation. The liquid membrane forms a strong seal and makes a permeable layer to enable moisture to evaporate off. Size is 4m x 4m. The advantage of laying the insulation layer under the screed is that it can be laid inside a sheltered building on a dried slab after the roof is finished and that the dpm, whether over or under the insulation layer, can more readily be joined to the dpc in walls, as illustrated in Fig. JB Flooring Well-Known Member. blocking/nogging for support of plasterboard 43mm x 38mm. As you would expect, you need as much heat as possible to flow upwards and into the room. 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. 4 so you have around 1. It stops around 10mm away from the internal walls in all rooms. applications are suitable for bonded topping screeds. 2 Feb 2010. 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 only way to tell properly, is to carry out a proper test. I would think a strip out and start again would be your best option, you should consider where/why there is water evident before. 1314. Screed & Insulation. However, when I hammer-fix the battens to the concrete I'm going to punch holes in my DPM. I will be tiling over the screed so looking for the simplest option. Figure 2: Concrete floor cast into rebate in foundation wall. 28 Sandiwch damp-proof membrane. Country. . Pro-Screed Gold is suitable for application over most underfloor heating systems. Wet underfloor heating. 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. Non-structural floor screeds shall be adequate for the location and intended use, and provide a suitable background for floor finishes. Floor under carpet marked with chalk for wet areas. Ball and Co. You also should have removed the vinyl tiles before priming and screeding. Last autumn we knocked down an old conservatory and kitchen extension and built a new extension in the same place. Posted July 28, 2021. Effectively, a damp proof membrane (DPM) is used to create a barrier between a concrete (or screed) subfloor and a wood floor. Solid floor insulation –screed finish: Per m 2: £70: £90: £80: Labour: Per day: £180: £250: £215:. 50 Ex VAT £21. Damp Proof Membrane is intended for use within solid concrete floors to prevent the rise of moisture or damp through structure flooring. The surface should be of sufficient quality and. 40mm traditional sand and cement screed. Prime and reapply , then screed to level and tile. However the tiler should apply a Primer before screeding such as StopGap P141. The. framing joints secured with not less than 2 nails per joint. If there was no dpm I would suggest a uniformal distribution across the whole floor. The advantage of having the foundation. Brian McNaughton & Son Ltd. British Standard (8204:1) says minimum 65mm for domestic floating. Property is mid 1960s, solid ground floor. top of my concrete slab was about 50mm below DPC, I finished with battens and floorboards. With the number of planning applications for basement extensions rising by 183% according to research by Halifax, tilers need to be. For an excellent balance of. The Epoxy DPM 5kg is supplied in two 2. 4,049. DPM is usually below the concrete, then the insulation, then a polythene sheet to stop the insulation floating as the screed is poured. Can be used as a Damp Proof. Reinforcement is required when you’re concreting areas that will be subjected to heavy loads, such as garages and car parks. A laminate wll be glued onto that. This barrier is intended to stop moisture passing from one to the other. The position would vary in accordance with proposed methods of construction. The dpm is extended and taped around this opening. At the moment, there is a dpm under the patio door overlapping the cavity and meeting the main dpc which comes up from the slab and wraps around the inner bricks. Insulation Below A Floor Screed. Ideal for use where there is no functioning structural DPM (common in older properties). 5. 22) Steel. We used the Ultra Floor system, Ultra DPM-it,. 27 Dec 2020. Mapeproof One Coat can be used with underfloor heating systems providing the system has been fully commissioned as per BS8203 2009, Section 3, 3. adamhardy Member. The DPM should extend up the external foundation walls to meet. Which is supposed to be a DPM equivalent. Trusted Trader, said safety must be a priority after a flood. I moved into my new build nearly 2 months ago now and am having quite a few issues. The tiler can then latex or screed over the DPM. Used the primer neat as guidelines suggested. 75mm pir but we have decided on 100. Ask yourself where the gallons and gallons of water in the slab are going to go - apart from potentially lifting the DPM it will come through any defects in the DPM and cause problems. 9. Bring the membrane up the surrounding foundation walls until it is just high enough to connect with or form the wall damp proof course. Then a primer like the one you have at 4-1 then if needed another coat at 2-1. Some slate or concrete board should then bridge the cavity gap. i'n not farmiliar with wickes dpm and the primer used for professional (if you like) screeds is neoprene. To avoid damage to the insulation layer and the dpm it is necessary to take care in tipping, spreading and compacting wet concrete or screed. Can be used as a Damp Proof Membrane on sub-floors not under hydrostatic pressure. You now have a 'swimming. Fit a damp proof membrane as above, then lay a separation layer. All other sheet membranes can be used with unbonded toppings. The old floor tiles do contain a small amount of asbestos ( Marley tiles etc. The problem is by the time we insulate, screed and lay the flooring we will be above the dpc& membrane level by 4 inches. Could us a liquid dpm like Drybase (2 coats), then a sand/cement screed,with fibre reinforcment, 25mm is the minimum thickness for bonded screed, that's thin,might still crack, no need for primer with Drybase. Stack Exchange Network. Our highly experienced team of technical experts are here to offer help and advice every step of the way! Dependable Deliveries. Where screed is laid on top of insulation, screed should have a minimum depth of 65mm. £20 per m2. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. Fig. 4. 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. 16 Nov 2016. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. Needs a dpm under it and i normally put one on top too - stops you accidentally sticking the boards to the insulation. RFC Liquid Damp Proof Membrane (DPM) is a professional 2-component applied surface primer. The concrete slab was usually 100 to 125mm thick. Ok so I have drawn the attached image. heating installations with cementious screeds provided a temperature of 27°C is not exceeded. 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). DPM's must be carefully protected where folded up the perimeter walls, and lapped under the DPC particularly at door openings. 250mu (1000G) Black Polythene Damp Proof Membrane (DPM) 4m x 25m (100m2/Roll) URN: 5004075. Mastic Asphalt – this is the earliest form of liquid DPM and is usually laid on the top of another membrane or a fibreglass surface. The floor make up is compaced hard core, 125mm concrete, dpm, 100mm insulation, 75mm concrete screed ( polished and heated). I would also gripfill under the plate to supplement the fixings if it were screed. Mapeproof One Coat is not recommended for heated subfloors where wood floor coverings are to be installed. 4 Screed. 22 August 2019 at 10:27AM. Walkable in 6 hours. 34. (DPM) with joints well lapped and folded. Many can be used over a variety of existing uneven substrates, using gravity to allow the latex mixture to self-level. The bitumen adhesive also contained the same asbestos fibres. weberfloor DPM can be applied on to concrete or cement based screed surfaces with a. weberfloor DPM can be applied on to concrete or cement based screed surfaces with a. It’s primarily designed for brushing onto concrete floors and fine concrete screeds. Liquid DPMs gave the best protection but were more expensive. FlexiDry said: Yes laying the screed direct onto insulation is standard practise for a floating floor. 17 May 2010. hot bitumen, or cold bitumen in solution. 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. Cement screed is the most commonly installed type of screed and is suitable for both interior and exterior surfaces. The screed will be only ~50 max (not yet dug any up). 4 Screed. Laying new floor - needs DPM? dunroving Posts: 1,881 Forumite. Pre screeding, you lay the DPM, install the insulation sheets and create vertical upstands of insulation block around the outside perimeter of the wall. 150mm PIR insulation. 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. . When sand-blinded, BAL DPM allows tiling onto difficult substrates such as steel. The clips only pierce the thinner layer above the insulation, which is only really there to ensure an unbonded concrete/screed above. I intend to consult BC but would like to educate myself before I speak with them Thanks in advance. 28. 1: Fill the gaps with concrete and get an asphalt company to lay an asphalt screed over it to restore the DPM. Insulation must be provided under their entire area to ensure compliance with the Building Regulations is achieved. I could put the dpm under the concrete which would be as effective. Let the slab dry first. Anyway, my DPC/DPM seems to have been done wrong, but I just wanted to ask what I should do next to make it work. 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. I was planning on putting 1200g DPM down, then 80mm celotex insulation (taped at joints), then 65mm screed (approx 1. 90 per pack | Buy now from UK Flooring Direct. Since that period I've take out the bitumen screed/dpm and been on the concrete slab since about mid February/March. 4. Just lap the whole room up as normal, blobs of. Wet underfloor heating installation cost. This could have been avoided by building the membrane on to the inner leaf only and protecting it with a 100mm DPC, or by protecting the wide horizontal DPC with an. Gaz, you need to change your message setting as I can't reply. In the attached photo I have removed poorly laid DPM and insulation boards with a view to starting again. hallbeck New Member. BS8203 recommends a maximum of 75% RH prior to the installation of sensitive finishes. It's a complete lack of knowledge on your floorlayers part or possibly just a carpet fitter trying his luck. When sand-blinded, BAL DPM allows tiling onto difficult substrates such as steel. The position would vary in. Small domestic areas that are going to have carpet, wood or synthetic floors as the final surface are ideal to use in conjunction with. 2 of the internal walls in the older building will be left as bare stone,. CS Flooring. 2. Through DPM of course so a bit of silicone down the screw hole to seal the hole. Alan Jackson - Commercial Manager UK and Ireland - Gypsol. -markie-, Feb 10, 2020. Effectively, a damp proof membrane (DPM) is used to create a barrier between a concrete (or screed) subfloor and a wood floor. We are one of the leading manufacturers of advanced barrier technologies and design-based solutions for specifiers, contractors and builders merchants throughout the UK and Europe, you can count on Visqueen for product quality. uk ;. Packaging: 25kg bags. Remove and Smooth. 15 Feb 2015. Spoke to makers of UFH system. Unbonded Sand and Cement Screed Minimum Thicknesshelppppppppppppppppppppppppp just had to quote for screed flooring. LAY DAMP PROOF MEMBRANE. However the tiler should apply a Primer before screeding such as StopGap P141. Ie work down from FFL. doors. Option 1 is clearly cheaper but as long as it takes a screed floor (says it does) and gets signed off by. 2m3). Damp Proof Membranes. Renovation of more than 25 per cent of a solid or suspended floor involving the replacement of screed or a timber floor deck would have to meet the standards required by the building regulations Approved Documents. Our team of highly experienced technical experts are always on hand to provide the highest level of support and advice to our customers. 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. USES For priming, consolidating and sealing of: Absorbent and non-absorbent sub-floors, consolidat-ing weak cement screed and isolation of old adhesive residues. DPM sheets should be overlapped by at least 300mm. Brian shows how to correctly fit a Damp Proof Membrain - DPM in a new build houseLink to the T-Rex tape Website Http://bodgeitwithbri. Ground-bearing concrete floor slabs should be protected against ground moisture by providing a continuous damp proof membrane (DPM). It is also recommended that light reinforcement be used. Ideally I don't want to screed the floor inside now as it will primarily be a workshop so I'm trying to retain as much of the 2. 21. Onto the concrete. An expansion gap may be necessary around the edge of the floor finish in screed or. DPM (1200 gauge visqueen) Old Concrete Slab. Hi, Thanks for this, so it sounds like you would normally just overlap (and seal) the floor DPM and one over the threshold which extends to the outer leaf? I've filled the cavity with concrete under the door opening and poured the slab and the screed will go across the cavity to the outside leaf (which has the perimeter insulation to stop cold spots). For unbonded and floating screeds, a DPM may be specified between the base slab and the screed. WoodYouLike. 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. Made from a combination of sand, cement and water, usually in a sand/cement mix ratio of anywhere between 3:1 and 5:1. 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. Norfolk. PermaSEAL Liquid DPM can also be applied to concrete floors below screeds. "Document any damage for insurance purposes. #1. Screed on top of slab is cracked/crumply/blown so that’s come off and now down to the concrete. The tiler can then latex or screed over the DPM. Side extension refurb: old concrete slab is uneven with a line of about 10mm difference in heights down middle, and dpm under screed is visibly not 100%, with a few gaps. You must design out the (damp/thermal) vulnerabilities associated with raft type foundations as they can be a headache. It still might not have a DPM under the floor. 3. Cement screed. 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. Water under tiles. 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. above the slab I am having a screed to cover the UFH pipes. com Do I need a DPM under laminate flooring? Simply put yes. 0. Issues to be taken into account include: installation. 5mm Polyflor . Temporary protection should be given As proven in this Celotex Floor Insulation Guide, Celotex insulation is a versatile and effective flooring insulant. dthobhani; 18 Mar 2011; Floors, Stairs and Lofts; Replies 2 Views 1K. We always remove the masonry below allowing the floor screed to have a bit of 'meat' to help overcome the differential movement. Types of Liquid DPM. +44 (0) 333 202 6800. Your privacy. The minimum sand and cement screed thickness would be 40mm as defined by the British standard. I am the Managing Director of the Multi-Award Winning Speed Screed. They can therefore be laid under the DPM (the DPM is still necessary to prevent. Hello, I have noticed some funny things going on under the floor of our recently bought house, which was originally built in 1905. 1. •Suitable for use on cement/sand screeds containing water based under floor heating systems •Apply ARDITEX NA direct without priming JUNE 2019 (SUPERSEDES MARCH 2018) PRODUCT DATA SHEET (43) V. #Screeding #Sc. Floor screed PIR cavity board Lay, level and compact the hardcore in layers (usually 150mm min / 250mm max). DPM, Celotex, 1000 gauge poly, 100-150mm concrete with or without reinforcement, 50-80mm screed. Currently, the central heating pipes and mains water pipes are all buried below the damp proof membrane, under the screed. The idea is that you are to prevent any screed material from falling down any joints and coming into contact with the cold slab. Firstly, there was no need to use a liquid dpm if you used underlay with a built in vapour barrier. This self leveling concrete’s use of latex. 13) Polypropylene. Beam and block floors may need a levelling screed or grouting to ensure base level. Alan Jackson - Commercial Manager UK and Ireland - Gypsol. I was with Mapei last week inspecting a failed DPM that had been laid on a subfloor with no DPM under it. . • GG300 – 300kPa. f) whether there is an effective dpm within or under the existing base; g) whether the screed is to provide the wearing surface, if so, the type and intensity of traffic to be expected; h) if not a wearing surface, the type and thickness of the finished flooring to be applied; i) type of underfloor heating (if any) to be used; applications are suitable for bonded topping screeds. 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. This barrier is intended to stop moisture passing from one to the other. However to get BC off your back you can use a epoxy DPM and sand scatter it before it sets. At the time of building the extension, due to new footings for structural walls to hold steels, drainage installed and the existing floor within the house showing signs of damp where the bitumen DPM had failed under floorboards nailed to the screed, I took the decision to remove all the floors, and oversited the whole house. So, as money's too tight to mention round here, I replaced the leaking door with a cheap UPVc one. 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. Insulation is laid on the concrete and covered with a screed. indd 2 08/08/2016 16:50:21DPM underneath and a plastic sheet on top to stop the screed getting between the insulation panels. Polycote DPM Primer is a superb twin pack high-performance epoxy coating that. If its not right. A full sheet DPM is 250 microns (1000 gauge) thickness or above. 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. The membrane is manufactured in standard 125mu, 250mu, and 300mu thickness and in roll sizes of 1. Step 3: Lay the watertight membrane. A Damp Proof Membrane or DPM is a waterproof barrier that’s introduced between your sub floor and your wood floor. Find. 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. I was then able to put in a dpm and a hefty layer of cellotex and then screed to the level of the house. Also there MUSt be a DPM under the screed to stop any substrate moisture coming up from underneath as a result of heating. This is resorted to only under the duress of severe time constraint. Ideally with a screed pump. Customer asked me how did they stop rising damp before the Dpm sheet was used and it made me think ( that hurt ) . Registered Office: 6 Acre Close, Rustington, West Sussex BN16 3PG. Diagram B38 - DPM lapping under DPC for thickness of inner leaf. Visqueen 2000 gauge Polythene - 12. All modern buildings have what is known as a Damp Proof Course. i'n not farmiliar with wickes dpm and the primer used for professional (if you like) screeds is neoprene. The oversized DPM was instead lapped with the DPM that was placed under the screed. 25 Apr 2010. Learn More Damp Proofing 15 Items DPM Handy Pack - 300mu 1200 gauge - 4m x 5m Rating: 2 £17.