It's a complete lack of knowledge on your floorlayers part or possibly just a carpet fitter trying his luck. In both cases the surface on which the dpm is laid needs to be as smooth as possible. Hoping the power of the Screwfix forum can help with a totally baffling problem we are having with our new extension. I would guess, that a standard mix was used, as that would be cheapest, so could assume 1mm per day, but that`s why a test would be needed. The current pipes to it will be diverted to another drain to the left of the photo. As you would expect, you need as much heat as possible to flow upwards and into the room. I would lay the DPM straight onto the existing and screed over. . Depends where the UFH pipes are. Ideal for use in shower areas where screeds are laid to falls incorporating a damp proof membrane. jonathanc Guest. 6 March 2017 at 8:04PM edited 6 March 2017 at 8:59PM. 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. I moved into my new build nearly 2 months ago now and am having quite a few issues. Reaction score. All waxes or sealers must be removed, and patching/leveling or embossing must be brought to a flatness of 3/16” in 10’. Self levelling compound was laid straight on top of the concrete floor (with no primer). I would use 100mm x10mm frame fixings, especially in screed because it is weak. Care must be taken to a) ensure there are no holes or tears in the sheet that could allow. DPC and DPM are lapped together at this stage. 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. Based on a screed done in 1963 I’d say 95% there won’t be a effective damp proof membrane under it so a epoxy dpm should of been used like Ardex DPM1c. Refer to manufacturer’s guidelines. This barrier is intended to stop moisture passing from one to the other. Firstly, there was no need to use a liquid dpm if you used underlay with a built in vapour barrier. 2. #2. 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. 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. Just lap the whole room up as normal, blobs of. The Epoxy DPM 5kg is supplied in two 2. One thought is to plug it at the junction under the draincover and then screed round it, and lay floor over; then it can be reinstated in future if ever needed. Telephone: 0800 270 7837. Assuming 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. Overlap it and tape it with duct tape or 100mm pvc tape. take account of possible differential movement. Sunny Hampshire. Two coats will provide protection up to a maximum hygrometer reading of 95% RH. i'n not farmiliar with wickes dpm and the primer used for professional (if you like) screeds is neoprene. Ultraplan Renovation Screed 3240 is suitable where good resistance to loads is required, also for castor wheel traffic and underfloor and undertile heating systems. 25 Apr 2010. Mapeproof One Coat can be used with underfloor heating systems providing the system has been fully commissioned as per BS8203 2009, Section 3, 3. Pumped anhydrite floor screeds are not much dearer than ready-mix sand/cement, costing around £25/m3 (laid. Country. . Can be used as a Damp Proof. Packaging: 25kg bags. 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. "Remove water with pumps or buckets and contact your insurance company straight away. • Unbonded (i. Epoxy DPM itself (the actual product epoxy) wont fail once set. Onto the concrete. 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. Can you put DPM over screed? Liquid DPM is a system that is used over a base floor. 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. 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. DPM Membranes for Concrete Floors A range of high quality DPM membranes from Capital Valley Plastics, designed for use with solid concrete slabs. Apply ARDEX DPM 1 C to protect the floorcovering installation from residual construction moisture and ground bearing moisture. 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. But others are direct to earth, brick, rubble what ever. Then mix up the high performance stuff as that is fibred and can be taken to a feather edge. This reduces the risk of harmful interstitial condensation by ensuring that any moisture within the. 15 Feb 2015. £18 - £22 per m2. 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. Checkatrade offers the following guide: Electric underfloor heating cost. The dpm needs to be clean and dry. Small hole dug through 2" soft sandy concrete to reveal hardcore and soil. Bonded Screed Maximum Depth. 10 Feb 2020. DPM over a new underfloor heated screed, the heating system must be turned off 48 hours before application. 25W/m 2 K to meet with building regulations, even if you didn’t plan to. Reinforcement is required when you’re concreting areas that will be subjected to heavy loads, such as garages and car parks. 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. Read more about changes to thermal elements 1 (in the 'External Walls' section)The removal leaves a surface the bonding agent can bond to, ensuring the screed does it’s job. rip some 18mm ply. 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. TB243. But on the basis of more insulation is better, consider fitting more and laying cupboard flooring on top, or on joists. link with wall DPCs to form an impervious barrier to prevent moisture reaching the interior of the dwelling. M. if no dpm I would blackjack 2 coats on. 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. 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. RFC Liquid Damp Proof Membrane (DPM) is a professional 2-component applied surface primer. Visqueen ECO Membrane Data Sheet. – the UK’s leading manufacturer of flooring adhesives and floor preparation products for the contract flooring industry. Yes run the dpm up the wall to connect wall dpc with floor dpm. New-build install: £120 to £135 per square metre. It’s primarily designed for brushing onto concrete floors and fine concrete screeds. If modified screed is used you can get down to 55mm. The guy doing it tried to compensate by using more adhesive and most of the wood has. This allows for the full 5kg or just half to be mixed at once depending on the area to be covered. 1 Feb 2010. Flexible - easy to detail and install on site. The lower sand ratio means a higher ratio of cement, which gives a stronger mix. UFH Pipwork. BS8203 recommends a maximum of 75% RH prior to the installation of sensitive finishes. 3) 50mm - Screed with Concrete Fibres, on top of the insulation boards. Walkable in 6 hours. If Under floor heating is used It is essential that the pipes are laid on. framing joints secured with not less than 2 nails per joint. 22 August 2019 at 10:27AM. ) chrysotile (white) asbestos fibres. indd 2 08/08/2016 16:50:21DPM underneath and a plastic sheet on top to stop the screed getting between the insulation panels. 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. 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. 0113 2455450 sales@rawlinspaints. hallbeck New Member. I have flowed screed planned for the finish rather than sand/cement. com. However the tiler should apply a Primer before screeding such as StopGap P141. 5kN/m2. #5. #1. This is resorted to only under the duress of severe time constraint. The subfloor in my house is a concrete slab with no DPM. 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. Greater thickness of screed may lead to a colder floor. 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. hours for Ceramics. Norfolk. . Brian shows how to correctly fit a Damp Proof Membrain - DPM in a new build houseLink to the T-Rex tape Website Http://bodgeitwithbri. First, divide the floor up. Fit a damp proof membrane as above, then lay a separation layer. 40mm traditional sand and cement screed. Generally fairly high grade stuff too. Tape is a non starter. 300 dries very hard Bitumen is soft so not compatible. BBA certified - third party accreditation. Is it possibly to lay a new insulated floor without a concrete slab, using only floor screed? For example: Level layer of hardcore; Layer of sand blinding; Damp proof membrane. This can only normally be guaranteed if its an new build or extension and most houses have been sold, inherited etc. The screed layer is damaged by damp, and is easily disturbed/crumbled. The polythene damp proof membrane (DPM) – generally a 1200 gauge- can now be rolled out into place ensuring the perimeter abutments are adequately covered. 6. Use polyethylene sheeting to create a waterproof membrane to ensure that there is no leakage of the screed when it is pumped in wet. 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. 16 Nov 2016. 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. Ie work down from FFL. Kingspan GreenGuard is available in a range of compressive strengths starting at 300 kPa 10% compression. Also checking, the dpm is meant to be underneath the insulation? Two options: - Jablite Jabfloor 70 100mm (or jabfloor 100 or 150 grade but not sure what the difference is, building merchant sells the 70) - Xthratherm/Kingspan 100mm. Try it free. It is not. For this, a metal mesh standing with plastic pillars ( (feet) will be laid before the concrete is. e. flooringman Well-Known Member. Last autumn we knocked down an old conservatory and kitchen extension and built a new extension in the same place. The surface should be of sufficient quality and. No mention of reinforced concrete screed. Complies with BS 8485:2015 + A1:2019 - industry standard for methane and carbon dioxide protection. This DPM is a ‘thick’ plastic sheet mostly 1000 – 1200 gauge polythene material. This is done to maintain energy efficiency and prevent. Staffordshire. 2. Hi All, I'm purchasing a new build and want to put Amtico Spacia down throughout the downstairs. We need to raise one level by 6mm then screed then laying 2. Am hoping for UFH in screed (supplied won't do 50mm, only 65mm). Thanks for reading. As a rough guide, laying conventional screed costs around £15/m2, increasing by around £5/m2 when delivered ready-mixed. Needs a dpm under it and i normally put one on top too - stops you accidentally sticking the boards to the insulation. The DPM (Damp Proof Membrane) is laid under the insulation on top of a soft blinding to ensure it is not punctured. The dpm is still continuous but laid down in the trough to maintain damp proofing. - Polythene membrane (DPM) - Insulation (rigid board type) - Concrete slab min. Ltd. Manchester • Member since 5 Jun 2015 • 64 jobs, 95% positive feedback. 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. There are two main options: 1. In terms of where the insulation should be placed, it can either be placed under the slab or between the slab and the floor screed. Hi, I'm doing a kitchen modernisation in my ex-Council house which was built in 1947. Renovation property: £135 to £185 per square metre. 00. rogerk101 likes this. A laminate wll be glued onto that. 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. 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. The OPTIM-R VIPs should then be fitted from the corner following the installation instructions. The DPM should: have sealed laps of at least 300mm wide. 5mm Polyflor . Air bricks are. SikaBond® Rapid DPM is a single part moisture curing polyurethane. #2. T ·Öà 4 ·Öò 8 ·Ñ• 2, Jun 15, 2007. Coverage: Approx 6 m at 3 mm thickness. The insulation should not be stepped as this can act as an anchor point and cause cracking in bridging or on the screed under movement and cause weak spots in a void underneath. 11 Protection against heat, and BS 8204 Part 1 2003, Section 6. 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. 14) Screed. or email. If you are just trying to take a hollow out get a long straight edge and use a marker pen to mark out the perimeter of the hollow. Don't use a bitumen at all, you are correct eventually your screed will fail. I will post up a pic of the failed LVT in a minute for you! Screed seems to be getting damper. The idea is that you are to prevent any screed material from falling down any joints and coming into contact with the cold slab. will come down and meet the insulation under the screed so the screed is totally floating. For traditional screed, the usual total will fall within the range £18. The screed has water anyway, so a bit of ingress isnt an issue. 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 or laminate. If in the screed then no problem with this. Insulation is a crucial consideration for UFH. Also, even with 80mm screed directly over Celotex the sab can feel a bit "hollow". 4,049. Moisture in the base will impede the drying of the screed. Curing Under Polythene 12 hrs 12 hrs Drying Time To Receive Finishes - from removal of curing polythene sheet 50mm thickness and 50% RH. As to joining - take bricks down to the bottom of the insulation later and run your insulation (which I presume is celotex type) into the opening, screed over insulation level. Fibreglass 1. above the slab I am having a screed to cover the UFH pipes. #2. 5kg multi chamber bags. Ball and Co. 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. I would also gripfill under the plate to supplement the fixings if it were screed. When stripping the bathroom, the area under the bath tub was bare concrete, lower than the rest of the "black" floor throughout the property. The surface should be of sufficient quality and. All modern buildings have what is known as a Damp Proof Course. Guidance on how to install insulation between a floor screed with Kingspan Kooltherm K103 Floorboard. Effectively, a damp proof membrane (DPM) is used to create a barrier between a concrete (or screed) subfloor and a wood floor. 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. A Damp Proof Membrane or DPM is a waterproof barrier that’s introduced between your sub floor and your wood floor. Guarantees the early laying of all floorcoverings. 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. . 0. 22 August 2019 at 10:27AM. +44 (0) 333 202 6800. e. 5-10mm thick. AN INTRODUCTION TO. . do I still need a DPM under that insulation? it is internal and sitting on a structural slab that is wrapped in DPM externally. 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. The mat seperates the UFH and the (normally) floor tiles, and allows them to expand at different rates, so stops the tiles cracking. Location. The concrete slab was usually 100 to 125mm thick. 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. Relative Humidity: The moisture content or relative humidity of the atmosphere plays is a major factor that affects the drying time of the screed. 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. 55mm of TS15 will impart around 1. Then the lamiante has trapped this water in creating the sweat. AFAIK - PIR insulation boards need have a DPM under them to protect the board. g. The Concrete slab will have been placed in January so it's had about 8 months to dry out. This seems to have been used in abundance before the original screed was put down. Screed. It is good practice to either fit another DPM or tape the insulation joints, when adding a screed on top of inso'. I really need to get the living room useable for my family and am hoping that a dpm under the engineered wood is possible. It stops around 10mm away from the internal walls in all rooms. Labour costs. Sand / Cement screeds must have a moisture reading of less than 75% RH before work. DPM is normally used in floors. Im not quite sure where my DPC should be going. Fig. The DPM we use does not cancel all moisture out as this will end up. How to Damp proof a floor and walls using synthaproof as a damp proof membrane is shown in this tutorial. Checkatrade offers the following guide: Electric underfloor heating cost. TF. #3. Developer has quoted £3744 for approx. 50 Ex VAT £21. These tiles have failed as some are missing/ some broken/ the bitumen broken down, meaning the DPM has failed, hence allowing the water through. co. DPM's must be carefully protected where folded up the perimeter walls, and lapped under the DPC particularly at door openings. I don't understand how to bridge the cavity under the bifold without filling the cavity or compromising on structural strength. DPM sheets should be overlapped by at least 300mm. Country. I think this is too expensive, so got a quote of another supplier of £2565 plus any potential floor preparation, with latex screen costing £13 /sqm or a feather finish at £2. Its an easy job to do yourself - also check Seconds & Co for PIR. ), then 500 gauge plastic (or just use the leftover 1200 gauge DPM) then 100mm concrete slab. If the applied DPM is still very tacky, this1. Maximum depths are around 10-15mm, however with the addition of bulking aggregates (normally kiln. Use 1000 gauge or thicker – ideal for this is the polyethylene use for the DPM under your concrete subfloor. The old adhesive should of been removed. The floor originally had a carpet laid on top of the tiles, when I lifted it nothing felt, looked or smelled damp. It may be applied onto either a solid in-situ concrete ground floor slab or onto a precast concrete floor unit. Stack Exchange Network. Renovation property: £60 to £85 per square metre. Assuming for now that the DPM is below the screed (not yet found that out), I'll need to penetrate the DPM and cut into concrete for the waste pipe. Apply sand-blind base (this base should be level to within 5mm along any 3m straight edge). My DPM was these tiles that were bitumnned/black jacked to the floor. 19)Cement. Alan Jackson - Commercial Manager UK and Ireland - Gypsol. Pricing. 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). Whilst looking at the overall prices of each piece of work there's a couple of questions that have come up. £20 per m2. To remove the screed in order to relay a DPM is, in most cases, completely unrealistic and actually completely unnecessary. The insulation level and fabric of the building should always be factored into an underfloor. Which way would you go, 1000 gauge plastic under slab OR liquid dpm between slab and screed? renovateduk, Jul 17, 2009 #3. 3. 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. 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. For guidance on using DPM One Coat Membrane with screed products refer to the individual ScreedPro Data sheet concerned. Then use the correct screed. Property is mid 1960s, solid ground floor. you then have a continuous damp couse not inportant if concrete above dpc level. Mastic Asphalt – this is the earliest form of liquid DPM and is usually laid on the top of another membrane or a fibreglass surface. Was looking to do liquid DPM sandwich with fball 1200/F77/1200 (or NA/1cDPM/NA but that’s costing another 30% more. The concrete slab was usually 100 to 125mm thick. Out of the 7sqm of floor i guess about 1. 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. Cement screed. The DPM (Damp Proof Membrane) is laid under the insulation on top of a soft blinding to ensure it is not punctured. If there is an operational DPM beneath the concrete you don't need one on top. 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. An ARDEX Damp Proof Membrane will protect the floorcovering. Suitable for most construction damp proofing requirements. The specific liquid DPM system will depend on the type of substrate or screed. Issues to be taken into account include: installation. We provide a range of solutions including DPM screed, flooring primers and more! We are also radon barrier suppliers, making us perfect for all your needs! Call: 0330 223 2364 ; Email: estimating@cscscreeding. 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. They can therefore be laid under the DPM (the DPM is still necessary to prevent. In terms of where the insulation should be placed, it can either be placed under the slab or between the. Issues to be taken into account include: installation. 500g Single Wound Polythene-2. An expansion gap may be necessary around the edge of the floor finish in screed or. Then a primer like the one you have at 4-1 then if needed another coat at 2-1. Like a lot of houses of that age, the ground floor is bitumen/asphalt over a concrete screed. Temporary protectionI had part of a 9" wall knocked down for a doorway. Insulation will then go on top and the screed layer would go over the whole lot. weberfloor DPM can be applied on to concrete or cement based screed surfaces with a. Hi All come across this forum and would really appreciate some assistance. You need a flooring professional to use an epoxy liquid DPM and screed suitable for this area and is not a job you should think to attempt 1 pinhole is a failed 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. 12) Tiles glued. Lay the damp proof membrane (DPM) (normally 1200g polythene sheet/300g micron or a radon barrier if specified), over the sand-blind base. 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. P. Proposed floor is pitch pine boards secret-nailed to 2 x 2 inch battens with insulation between, onto a concrete floor not known to have a DPM under it; therefore, DPM to go under the battens. Mark El-Kadhi New Member. #7. Location. Under ambient conditions, PALACE 1-COAT DPM is ready to receive a smoothing compound as soon as 4 - 5 hours after application. This will allow the screed to bond to the dpm. #3. Had a look at the pics and IMO no dpm under the subfloor. DPM, Celotex, 1000 gauge poly, 100-150mm concrete with or without reinforcement, 50-80mm screed. carpet, tiles etc. If you are using a final floor finish which will be fixed to the screed’s surface using an adhesive then you will need to lightly sand the laitance off the surface of the screed before using a compatible primer and adhesive. They can feel wobbly when you walk on them but you get to the point when you can't get them any better and each give you walk on them or lift them you end up going around in circles. PermaSEAL Liquid DPM can also be applied to concrete floors below screeds. Non-structural floor screeds shall be adequate for the location and intended use, and provide a suitable background for floor finishes. Once set, you can then apply your screed flooring to the DPM. The job is under Building control, so I'm sure the inspector will like a nice solution as well! The shower can't be lifted higher (elderly. This generally takes 1-2 days, depending on the thickness of the floor screed. If you are installing where existing floors have been removed, check that there are no traces of previous adhesive residue. Discussion in ' Builders' Talk ' started by barnjules, Jan 30, 2017 . Top. 2. Bostik Screedmaster Rapid DPM is a ready for use; one part, water-based damp proof membrane. I am assuming its asphalt with a bitumen top layer, 10-15mm thick. Non-structural floor screeds shall be adequate for the location and intended use, and provide a suitable background for floor finishes. However to get BC off your back you can use a epoxy DPM and sand scatter it before it sets. #1. When stripping the bathroom, the area under the bath tub was bare concrete, lower than the rest of the "black" floor throughout the property. As a rough guide, laying a conventional sand/cement screed costs around £15/m2, increasing by around £5/m2 when delivered ready-mixed. How to install vacuum insulation panels below a floor screed. 0m is a low density polythene membrane for use under floor screeds which are not subject to hydrostatic pressure, to protect buildings against moisture from the ground. i'n not farmiliar with wickes dpm and the primer used for professional (if you like) screeds is neoprene. 3. Can anyone help me with the DPM under a stud partition? What's the usual way of putting it down when you're dividing a room. if your DPM were above the concrete, the uFH would be heating a large damp lump of concrete. 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. All other sheet membranes can be used with unbonded toppings.