weberfloor DPM can be applied on to concrete or cement based screed surfaces with a. 4 so you have around 1. 100mm thick (can be heated) - Levelling screed (as required: self levelling compound, sand/cement screed etc) - Flooring, e. 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. Wet underfloor heating installation cost. 1200g dpm. Can you put DPM over screed? Liquid DPM is a system that is used over a base floor. For unbonded and floating screeds, a DPM may be specified between the base slab and the screed. having a solid wall causes damp bridging problems for the floor (there is a dpm on top of the floor anyway, but the beam and block is supposed to sit on a dpc) as there is no cavity. Damp proof membranes (DPM) A DPM should be a minimum thickness of 1200g polythene and linked to the DPC with a minimum 100mm overlap. 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. You are talking about a solid concrete floor which has to be on load bearing stable ground. It originally had Marley tiles stuck down with bitumen 'glue', but many of them are missing and I will remove the rest. Our quarry tiles were pretty much laid on dirt so there were some big variations in height over the whole kitchen. 65mm Screed. 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 membrane is manufactured in standard 125mu, 250mu, and 300mu thickness and in roll sizes of 1. Apply sand-blind base (this base should be level to within 5mm along any 3m straight edge). either way, as the other posts say, you would be better screeding which will also take out any irregularities in the concrete. hallbeck New Member. someone suggested removing the blocks on the inside along the width of the bifold and screeding all the way to the brick course. I'd like to change our tiled dining room room floor to a carpeted floor with underfloor heating. g. This DPM is a ‘thick’ plastic sheet mostly 1000 – 1200 gauge polythene material. Location. Cement screed. UFH inside plastic polypanels 75mm screed (probably not liquid). The builder wants to apply a DPM to the top of the slab before it is dry. Tramex reading at the time of vinyl removal was 3-4+. The plan was to lay American Black Walnut but the hallway floor was not level. Laying new floor - needs DPM? dunroving Posts: 1,881 Forumite. 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. #5. 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. This barrier is intended to stop moisture passing from one to the other. carpet, tiles etc. But if you’re on a tight schedule, allow at least 7 days before applying your vinyl floor covering. Maximum depths are around 10-15mm, however with the addition of bulking aggregates (normally kiln. Spoke to makers of UFH system. 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. If its not right. It stops around 10mm away from the internal walls in all rooms. 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. 74 inc. We need to raise one level by 6mm then screed then laying 2. so FBall seems the way to go). 2. For rafts, DPM and screed must be on top of raft and screed must be at least 65 mm thick. AFAIK - PIR insulation boards need have a DPM under them to protect the board. The bitumen is about 20 mm thick and, I believe, serves as moisture barrier as well as an 'appearance' finish. 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. #1 CGN Screwfix Select andyscotland said: ↑ The concrete slab I poured for my utility room extension is slightly uneven - a small dip into the centre. not bonded to the base – typically where a DPM is placed under the screed. A latex based screed isnt as affected by moisture/damp as a water based is. This allows for the full 5kg or just half to be mixed at once depending on the area to be covered. 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. But others are direct to earth, brick, rubble what ever. Checkatrade offers the following guide: Electric underfloor heating cost. Pre screeding, you lay the DPM, install the insulation sheets and create vertical upstands of insulation block around the outside perimeter of the wall. 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. Epoxy DPM itself (the actual product epoxy) wont fail once set. Solid floor insulation –screed finish: Per m 2: £70: £90: £80: Labour: Per day: £180: £250: £215:. Care must be taken to a) ensure there are no holes or tears in the sheet that could allow. Two coats will provide protection up to a maximum hygrometer reading of 95% RH. However the tiler should apply a Primer before screeding such as StopGap P141. Then a primer like the one you have at 4-1 then if needed another coat at 2-1. Insulation is a crucial consideration for UFH. then ducting should be provided to allow air through the solid floor and into the void under the existing house. All other sheet membranes can be used with unbonded toppings. This will allow the screed to bond to the dpm. No need for double DPM. Since that period I've take out the bitumen screed/dpm and been on the concrete slab since about mid February/March. The screed layer is damaged by damp, and is easily disturbed/crumbled. Lay the dp membrane over the concrete slab and lapped over the brickwork. 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. 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 was hoping to use a recycled content DPM. As with the Kooltherm installation, start by ensuring a clean and level surface. It’s primarily designed for brushing onto concrete floors and fine concrete screeds. 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. it could easily be up and down by up to 15mm. Description. 50 Ex VAT £21. Country. The old adhesive should of been removed. #1. 4. As you would expect, you need as much heat as possible to flow upwards and into the room. 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. 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. This will leave bitumen (ironically) glue residue behind which is a problem to remove I believe - and must be completely gone. Concrete & Sand/Cement Screeds Concrete and sand/cement screeds must be dry and any laitance or surface treatments removed. I could put the dpm under the concrete which would be as effective. enquiries@visqueen. DPMs on top of the slab, i. With the number of planning applications for basement extensions rising by 183% according to research by Halifax, tilers need to be aware. DAMP PROOF MEMBRANE. Replacing over half of your floor will mean you’ll have to insulate to at least 0. . A standard sand/cement screed would need to be laid at a minimum depth of 65mm for a domestic property. 11 Protection against heat, and BS 8204 Part 1 2003, Section 6. 5mm Polyflor . The specific liquid DPM system will depend on the type of substrate or screed. 5sqm has blown. There will be a damp-proof membrane under the insulation and possibly a second membrane on top, depending on the type of screed. 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. DPM sheets should be overlapped by at least 300mm. e. The lower sand ratio means a higher ratio of cement, which gives a stronger mix. However to get BC off your back you can use a epoxy DPM and sand scatter it before it sets. Definition of terms See full list on ecotileflooring. The dpm needs to be clean and dry. 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. He has sealed the joints as well so hopefully they won't squeak. Walkable in 6 hours. Small domestic areas that are going to have carpet, wood or synthetic floors as the final surface are ideal to use in conjunction with. £ 49. 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. Flowable liquid floor screed suitable for applying up to a depth of. California Country. Remove and Smooth. 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. Beam and block floors may need a levelling screed or grouting to ensure base level. also alot of the insulation manufacturers specify a 500/1000 gauge membrane between the insulation and the screed inkpad, Aug 6, 2009 #7. I was with Mapei last week inspecting a failed DPM that had been laid on a subfloor with no DPM under it. 2: Fill the gaps with concrete, lay a DPM over it, insulation, then a concrete / fibre screed. 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. The polyethene slip membrane installed over the insulation must be overlapped and sealed to prevent loss of screed. Laying new floor - needs DPM? dunroving Posts: 1,881 Forumite. 1, your new concrete will need drying time, approx 1 month for every inch, then a DPM is required. top of my concrete slab was about 50mm below DPC, I finished with battens and floorboards. 4,049. 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. 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. Hi, I'm doing a kitchen modernisation in my ex-Council house which was built in 1947. Walkable in 6 hours. A few months have passed since then and is now on average 2. Figure 1: Concrete floor slab and integral footing. £18 - £22 per m2. Capital Valley Plastics Ltd Damp-Proof Membrane Black 1200ga 25m x 4m (47163) (55) compare. Suitable for most construction damp proofing requirements. Lay the damp proof membrane (DPM) (normally 1200g polythene sheet/300g micron or a radon barrier if specified), over the sand-blind base. Issues to be taken into account include: installation. Hi All come across this forum and would really appreciate some assistance. New-build install: £50 to £75 per square metre. When it comes to the hearth I know that I need to have a constructional hearth at least 125mm thick that extends out 300mm in front of the stove. Most damp-proof floor coatings are applied directly to the concrete floor surface using a brush or roller. 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. The Epoxy DPM 5kg is supplied in two 2. Slightly below floor level are two layers of polythene membrane with a layer of floor levelling screed to make up to floor level. When stripping the bathroom, the area under the bath tub was bare concrete, lower than the rest of the "black" floor throughout the property. At its deepest it’s 150mm, what I’m stuck with is the builders trying to push on with the job. Use 1000 gauge or thicker – ideal for this is the polyethylene use for the DPM under your concrete subfloor. 100m² per roll. The work falls under building regs part L and you need minimum 70mm PIR insulation. Ltd. 17 May 2010. Pre screeding, you lay the DPM, install the insulation sheets and create vertical upstands of insulation block around the outside perimeter of the wall. Thanks for the reply. It is good practice to either fit another DPM or tape the insulation joints, when adding a screed on top of inso'. It’s only to stop the screed running under the insulation. BBA certified - third party accreditation. This can include timber floors, tiles, laminate flooring and carpet. Fig. Do you need DPM under screed? What DPM is Required? If the hygrometer reading comes back above 75% relative. 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. Warm construction build-up would be: - Sand blinded sub-base. DPM sheets should be overlapped by at least 300mm. 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. pf flooring, Jul 28, 2015 #20. Discussion in ' Builders' Talk ' started by barnjules, Jan 30, 2017 . com Do I need a DPM under laminate flooring? Simply put yes. Location. #1. studs 63mm x 38mm at maximum 600mm centres. water will be likely to collect between the DPM and the old floor. I was planning on putting 1200g DPM down, then 80mm celotex insulation (taped at joints), then 65mm screed (approx 1. The subfloor. 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. An ARDEX Damp Proof Membrane will protect the floorcovering. Roger Kenworthy on 2021-08-13 17:59:40: Question:Durability: A befittingly developed floor screed will outlast the else modules of the building. Liquid DPMs gave the best protection but were more expensive. 250mu Polythene DPM is suitable for use as a damp proof membrane under screed floors. Ground-bearing concrete floor slabs should be protected against ground moisture by providing a continuous damp proof membrane (DPM). Visqueen 2000 gauge Polythene - 12. Let’s hope you have a good water table as that’s the wrong dpm used. Ideal for use where there is no functioning structural DPM (common in older properties). Ideally with a screed pump. The previous concrete floor failed due to a lack of DPM and has now been removed. The subfloor. This barrier is intended to stop moisture passing from one to the other. But too much water will extend the drying time and. The purpose of DPM. Two coats will provide protection up to a maximum hygrometer reading of 95% RH. "Document any damage for insurance purposes. 1200g DPM will be fine. First, divide the floor up. I thought common practice was to tuck the DPM under the DPC, but mine is the other way around: I'm about to start taping the insulation around the studwork and then I'm going. To remove the screed in order to relay a DPM is, in most cases, completely unrealistic and actually completely unnecessary. Packaging: 25kg bags. 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. from a purely technical point of view a screed should always be divorced from the substrate by means of an operational DPM. 00. Don't use a bitumen at all, you are correct eventually your screed will fail. 17 May 2010. Damp Proof Membrane is intended for use within solid concrete floors to prevent the rise of moisture or damp through structure flooring. 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. link with wall DPCs to form an impervious barrier to prevent moisture reaching the interior of the dwelling. Out of the 7sqm of floor i guess about 1. If the DPM is still wet you should have not tiled over. 0113 2455450 sales@rawlinspaints. (See FeRFA Guidance Note No. 5kg multi chamber bags. 49 per m2. 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. Mapeproof One Coat can be used with underfloor heating systems providing the system has been fully commissioned as per BS8203 2009, Section 3, 3. 28 Sandiwch damp-proof membrane. Overlap it and tape it with duct tape or 100mm pvc tape. BS8203 recommends a maximum of 75% RH prior to the installation of sensitive finishes. 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. 45sqm to supply and fit. I was then able to put in a dpm and a hefty layer of cellotex and then screed to the level of the house. Brian shows how to correctly fit a Damp Proof Membrain - DPM in a new build houseLink to the T-Rex tape Website Http://bodgeitwithbri. dthobhani; 18 Mar 2011; Floors, Stairs and Lofts; Replies 2 Views 1K. 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. Outside ground should be. 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. This barrier is intended to stop moisture passing from one to the other. The tiler can then latex or screed over the DPM. The surface should be of sufficient quality and. Stack Exchange Network. 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. Learn More Damp Proofing 15 Items DPM Handy Pack - 300mu 1200 gauge - 4m x 5m Rating: 2 £17. 22 August 2019 at 10:27AM. Suitable for use with underfloor heating and for encapsulating electric cable undertile heating systems. It also looks like there could be polystyrene under the screed, this will be a barrier to damp coming from the ground. 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. Applying Damp Proof Membranes. We have our own in-house delivery fleet of FORS Gold vehicles with Moffett mechanical off-loads delivering nationwide. 001 Ardex Australia 2015 Bulding regs would require 100mm insulation and 70mm reinforced screed for this. Pro-Screed Gold is moisture tolerant and can be used under and over DPM’s. 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. The OPTIM-R VIPs should then be fitted from the corner following the installation instructions. DPM is usually below the concrete, then the insulation, then a polythene sheet to stop the insulation floating as the screed is poured. is that do-able? if so, can I just run the DPM 1 course above DPC? it's too late to tuck. In the attached photo I have removed poorly laid DPM and insulation boards with a view to starting again. As a waterproofer, BAL DPM is an easy two-coat system when used with BAL Self-Adhesives Butyl Tape in corners and junctions. We always remove the masonry below allowing the floor screed to have a bit of 'meat' to help overcome the differential movement. So I have a concrete floor in the kitchen (concrete - DPM - 50mm screed), knocked through into the outside toilet which just had soil floor. But on the basis of more insulation is better, consider fitting more and laying cupboard flooring on top, or on joists. Reinforcement is required when you’re concreting areas that will be subjected to heavy loads, such as garages and car parks. ARDEX DPM 1 C may be used if; 1. Floor screed PIR cavity board Lay, level and compact the hardcore in layers (usually 150mm min / 250mm max). 21. If you are getting up to the 50mm, you would question whether you want to use a smoothing product really just from an economic point of view,. 9. 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. 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 option of 50mm insulation between battens is appealing. They can be used under resin screed finishes and are applied in thinner sections than standard cement screeds. However the chance that the floor tiles or adhesive can release fibres and become respirable when disturbed is very low. Size is 4m x 4m. J. • GG500 – 500kPa. Yup so the plan is: Existing garage is concrete which is a 75mm lower than the current house level. High quality painting, plastering and drywalling tools. 5kN/m2. Use polyethylene sheeting to create a waterproof membrane to ensure that there is no leakage of the screed when it is pumped in wet. 6 March 2017 at 8:04PM edited 6 March 2017 at 8:59PM. screed. Also, even with 80mm screed directly over Celotex the sab can feel a bit "hollow". The DPM we use does not cancel all moisture out as this will end up. VAT £ 0. The difficulty is getting the underneath concrete to have a flat surface at exactly the right level. Floor under carpet marked with chalk for wet areas. Fast drying screed cost. What is liquid DPM? Liquid DPM is a system that is used. Jabfloor 70 has a nominal 1% compression value of 21kPa (2. 1200 Gauge DPMs should be used when a floor is direct to the ground. It's joining onto the garage I'm converting so the whole floor is getting built up with polythene DPM,. Vac up any loose sand once it's set and then tile. i'm you have gathered by now, you havn't left enough depth to do this. Our expert team are ready to offer you the very best solution for waterproofing. 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. 90 per pack | Buy now from UK Flooring Direct. Complete range, complete solution. 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. For traditional screed, the usual total will fall within the range £18. USES For priming, consolidating and sealing of: Absorbent and non-absorbent sub-floors, consolidat-ing weak cement screed and isolation of old adhesive residues. The idea is that you are to prevent any screed material from falling down any joints and coming into contact with the cold slab. 3. 5 ratio of cement to sharp sand. 6. 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. Step 3: Lay the watertight membrane. 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. If the coating is not going to be the final decorative surface and. Bostik Screedmaster Rapid DPM is a ready for use; one part, water-based damp proof membrane. Magnesite must be completely removed. 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. 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. pipes or cables for under floor heating should always be installed on top of the tanking membrane, not beneath it. As a rough guide, laying conventional screed costs around £15/m2, increasing by around £5/m2 when delivered ready-mixed. 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). (DPM) with joints well lapped and folded. Floor board overlaps new screed by 50mm so is supported by new screed on inside edge. 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. This should be laid on a bedding material such as screed which doesn’t damage the sheet and has fully sealed joints. Misinformed on this as he had put a dpm under the chipboard. The clips only pierce the thinner layer above the insulation, which is only really there to ensure an unbonded concrete/screed 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. 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. Some slate or concrete board should then bridge the cavity gap. Small hole dug through 2" soft sandy concrete to reveal hardcore and soil. Choosing the solid concrete ground floor insulation is important for any project. LKAB Minerals +44 (0) 7966 651006. Can you put DPM over screed? Liquid DPM is a system that is used over a base floor. Silicone mastic is the way to go. DPM, Celotex, 1000 gauge poly, 100-150mm concrete with or without reinforcement, 50-80mm screed. Because we were laying Karndean Flooring to a new extension we needed to check the % RH(relative humidity) of the concrete with a hygrometer. Pumped Anhydrite Screeds. With the number of planning applications for basement extensions rising by 183% according to research by Halifax, tilers need to be. Ultraplan Renovation Screed 3240 is suitable where good resistance to loads is required, also for castor wheel traffic and underfloor and undertile heating systems. 50mm C&S (1:4) screed towelled smooth. Preparation is key with these coatings and the substrate must be sufficiently clean and dry. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. 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. Should I lap DPM under or over Dpc then celotex, then another DPM lapped up the wall with 25mm up stands. Property is mid 1960s, solid ground floor. •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. I am assuming its asphalt with a bitumen top layer, 10-15mm thick. 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. Easy Handling & Installation. Can be used as a Damp Proof. Used the primer neat as guidelines suggested. The Epoxy DPM 5kg is supplied in two 2. Do your slab as intended, single course of brickwork around the perimeter, then build your frame. Ie work down from FFL. Guarantees the early laying of all floorcoverings. Price: £4. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. This self leveling concrete’s use of latex. The damp proof membrane (DPM), normally 1200g polythene or radon barrier, should be laid over the blinding,So not convinced glue down is right. Country. DPC and DPM are lapped together at this stage. Any existing floor screeds, coatings or adhesive residues. So latex one its more likely the addy will be affected. For unbonded and floating screeds, a DPM may be specified between the base slab and the screed. #1. The excellent adhesive qualities and quick drying time of Drybase Liquid-Applied DPM make it extremely versatile. 3. if no dpm I would blackjack 2 coats on. 22) Steel. DPM Membranes for Concrete Floors A range of high quality DPM membranes from Capital Valley Plastics, designed for use with solid concrete slabs. with the concrete but the insulation. You'll also need to take the dpm up the walls as well.