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. At its deepest it’s 150mm, what I’m stuck with is the builders trying to push on with the job. 150mm PIR insulation. 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. Can be used over underfloor heating. Jabfloor 70 has a nominal 1% compression value of 21kPa (2. 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. If the insulation is going below the slab, the damp proof membrane (DPM) is laid next, followed by the insulation, a polythene separating layer, and the concrete slab. Visqueen High Performance Damp Proof Membrane. But if you’re on a tight schedule, allow at least 7 days before applying your vinyl floor covering. The DPM should extend up the external foundation walls to meet. The surface should be of sufficient quality and. jeds. There will be a damp-proof membrane under the insulation and possibly a second membrane on top, depending on the type of screed. would it beneficial to change the floor structure to incorporate circa 250mm of eps insulation under the concrete slab, instead of the 150mm pir above. 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. not a good idea man. 49 per m2. Registered Office: 6 Acre Close, Rustington, West Sussex BN16 3PG. Our costs are ballpark averages – get a local tradesperson to quote now. A poorly compacted, damaged or weak screed should be completely removed by mechanical means and reinstalled correctly. if your DPM were above the concrete, the uFH would be heating a large damp lump of concrete. rev 2023. 034 W/mK, and is used to insulate inverted roofs, basements, car park decks, and heavy-duty commercial, industrial and cold store flooring. g. 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. It is also recommended that light reinforcement be used. Alan Jackson - Commercial Manager UK and Ireland - Gypsol. 00. Mark El-Kadhi New Member. 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. Screed & Insulation. You adjust the concrete slab to let your. It will - I believe - deteriorate with UV light, but that won't apply to anything cover by the soil itself. • GG300 – 300kPa. I could put the dpm under the concrete which would be as effective. Use 1000 gauge or thicker – ideal for this is the polyethylene use for the DPM under your concrete subfloor. 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. It is important to ensure that a proper seal is achieved around all services. 0113 2455450 sales@rawlinspaints. The damp proof membrane (DPM), normally 1200g polythene or radon barrier, should be laid over the blinding,So not convinced glue down is right. Firstly, there was no need to use a liquid dpm if you used underlay with a built in vapour barrier. e. Brian shows how to correctly fit a Damp Proof Membrain - DPM in a new build houseLink to the T-Rex tape Website Http://bodgeitwithbri. 5mm = 2. Insulation Below A Floor Screed. The option of 50mm insulation between battens is appealing. If applying a screed to Drybase® Liquid-Applied DPM, the second coat can be used as a primer if the screed is applied while the second coat is still tacky. 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. adamhardy Member. (DPM) between the concrete and screed. If the DPM is still wet you should have not tiled over. Property is mid 1960s, solid ground floor. 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. 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”. Ground-bearing concrete floor slabs should be protected against ground moisture by providing a continuous damp proof membrane (DPM). 17) DPM under slab. Developed to suppress residual construction moisture in cementitious subfloors including power floated concrete and sand/cement screeds. blocking/nogging for support of plasterboard 43mm x 38mm. Prime and reapply , then screed to level and tile. Hi, just laying insulation on 1200g DPM and now looking for a cheap / simple VCL to lay on top of the insulation and under the screed. Floor under carpet marked with chalk for wet areas. with the concrete but the insulation. 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. #3. DPMs on top of the slab, i. 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. • Unbonded (i. 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. The lower sand ratio means a higher ratio of cement, which gives a stronger mix. 2) 25mm - Celotex TB3000 Insulation Board. 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. Depends where the UFH pipes are. PermaSEAL Liquid DPM can also be applied to concrete floors below screeds. Screeds are covered by BS 8204, Screeds, bases and in-situ floorings, (2004). 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. Then a DPM on top to avoid them floating in the screed. Slightly below floor level are two layers of polythene membrane with a layer of floor levelling screed to make up to floor level. RFC Liquid Damp Proof Membrane (DPM) is a professional 2-component applied surface primer. A standard sand/cement screed would need to be laid at a minimum depth of 65mm for a domestic property. Our quarry tiles were pretty much laid on dirt so there were some big variations in height over the whole kitchen. Based on a screed done in 1963 I’d say 95% there won’t be a effective damp proof membrane under it so a. Then the lamiante has trapped this water in creating the sweat. Since that period I've take out the bitumen screed/dpm and been on the concrete slab since about mid February/March. Spacey Super Moderator Staff Member. 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. If DPM ok then. 21) Timber block. Complies with BS 8485:2015 + A1:2019 - industry standard for methane and carbon dioxide protection. O and the Answer to Mapei and Uzin is no. I laid the conc slab badly about 6 years ago ( did the whole shed in one hit 75m2, but my workshop is athird of the shed, so 25m2 wants levelling). Fibreglass 1. 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. This reduces the risk of harmful interstitial condensation by ensuring that any moisture within the. do I still need a DPM under that insulation? it is internal and sitting on a structural slab that is wrapped in DPM externally. As you would expect, you need as much heat as possible to flow upwards and into the room. Like a lot of houses of that age, the ground floor is bitumen/asphalt over a concrete screed. It is a thermally effective solution that is equally efficient in concrete floors, beam and block floors, and suspended timber floors. The Epoxy DPM 5kg is supplied in two 2. When incorporating under floor heating: Screeds should be isolated at all edges, abutments and columns to allow for movement due to thermal loadings; The manufacturers’ guidance for both the floor screed and the tiling must be followed to determine the minimum thickness of edge strip required to allow for expansion. It is not. Answered 18th Aug 2020. 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. Let the slab dry first. The purpose of DPM. The minimum sand and cement screed thickness would be 40mm as defined by the British standard. DPM is normally used in floors. Note though that this will raise the floor level by 75-100mm (depending on the insulation). Complete range, complete solution. The screed will be only ~50 max (not yet dug any up). Use a thick bed adhesive unless your competent to use screed, it takes skill and practice to create a flat floor. Because we were laying Karndean Flooring to a new extension we needed to check the % RH(relative humidity) of the concrete with a hygrometer. 100m² per roll. Developed to suppress residual construction moisture in cementitious subfloors including power floated concrete and sand/cement screeds. 19)Cement. Ideally with a screed pump. The company keeps abreast of market developments by. This should be laid on a bedding material such as screed which doesn’t damage the sheet and has fully sealed joints. The liquid membrane forms a strong seal and makes a permeable layer to enable moisture to evaporate off. Get it level then when it is dry and can screw through floor board into blocks. Ideally there should be suitable insulation below the underfloor heating pipe to resist the heat going downwards. The mat will get glued down to the screeded UFH, and then the. Just lap the whole room up as normal, blobs of. 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. 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. Produced from Recycled Material. 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. 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. 1200 Gauge DPMs should be used when a floor is direct to the ground. above the slab I am having a screed to cover the UFH pipes. You must design out the (damp/thermal) vulnerabilities associated with raft type foundations as they can be a headache. 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. #2. 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. 1. Start of next year i will be putting in my finished floor in our new extension, as it stand we got it water tight late last night with the glazing. They can be used under resin screed finishes and are applied in thinner sections than standard cement screeds. 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. . M. But this all begs the question of why the hallway is so wet. Developer has quoted £3744 for approx. Out of the 7sqm of floor i guess about 1. Insulation sheets should be laid tightly together with the joints staggered to avoid movement. #5. If you noticed the buildup wording is different to the detail drawing, it clearly shows dpm on top of concrete. So, as money's too tight to mention round here, I replaced the leaking door with a cheap UPVc one. To help determine the cost of a screed floor let’s look at the average prices people pay. 5kN/m2. DPC and DPM are lapped together at this stage. LKAB Minerals +44 (0) 7966 651006. I don't understand how to bridge the cavity under the bifold without filling the cavity or compromising on structural strength. DPM, Celotex, 1000 gauge poly, 100-150mm concrete with or without reinforcement, 50-80mm screed. 500g Single Wound Polythene-2. 250mu Polythene DPM is suitable for use as a damp proof membrane under screed floors. Then once the screed is dry use a liquid DPM such as F-Ball Stopgap F77. An ARDEX Damp Proof Membrane will protect the floorcovering. 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. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. I was then able to put in a dpm and a hefty layer of cellotex and then screed to the level of the house. Alan Jackson - Commercial Manager UK and Ireland - Gypsol. 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. – the UK’s leading manufacturer of flooring adhesives and floor preparation products for the contract flooring industry. The current pipes to it will be diverted to another drain to the left of the photo. 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. Fast drying screed cost. Step 3: Lay the watertight membrane. 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. The bitumen is about 20 mm thick and, I believe, serves as moisture barrier as well as an 'appearance' finish. We could scrape up the tiles and start again. Property is mid 1960s, solid ground floor. I think underfloor heating would work if you layed DPM, insulation (as much as poss) woodchip flooring and don't use a screed. top of my concrete slab was about 50mm below DPC, I finished with battens and floorboards. #5. This is a solvent, water free, epoxy resin and moisture tolerant curing agent that allows for immediate installation of moisture sensitive floor finishes onto concrete and. They are happy for the 25mm board to be laid on the screed, pipes clipped in then 9mm ply on top finally topped off with ceramics. Reinforcement is required when you’re concreting areas that will be subjected to heavy loads, such as garages and car parks. But too much water will extend the drying time and. Brian shows how to correctly fit a Damp Proof Membrain - DPM in a new build houseLink to the T-Rex tape Website Http://bodgeitwithbri. Flexible - easy to detail and install on site. Small domestic areas that are going to have carpet, wood or synthetic floors as the final surface are ideal to use in conjunction with. Do you need DPM under garage floor? Solid floor The existing concrete floor can be used as a base, however a new damp proof membrane (DPM). My questions are: Is there any reason to use a roll of DPM vs a liquid. If you are installing where existing floors have been removed, check that there are no traces of previous adhesive residue. ← Installation of rigid floor insulation on ground floor concrete substrates to receive screed. They can therefore be laid under the DPM (the DPM is still necessary to prevent. Ie work down from FFL. A section of the old screed layer has broken up around the edge of the patio door threshold. The total floor insulation cost will have two elements – the cost of materials and. We have a few options: 1. 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. 3. Walkable in 6 hours. +44 (0) 333 202 6800. The subfloor. Any advance on laying 75mm kingspan directly on existing screed with DPM beneath, then laying 18mm T&G moisture resistant chipboard. On a job that’s had anhydrite screed pumped in, using a Wolff gm200 moisture meter readings in parts are 99. For unbonded and floating screeds, a DPM may be specified between the base slab and the screed. studs 63mm x 38mm at maximum 600mm centres. Guarantees the early laying of all floorcoverings. DPMs on top of the slab, i. Which is supposed to be a DPM equivalent. floating construction then a second "slip". When sand-blinded, BAL DPM allows tiling onto difficult substrates such as steel. To avoid such issues, it is therefore extremely important to make sure that the screeds are given sufficient time for drying. 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,. 90 per pack | Buy now from UK Flooring Direct. royaloakcarpentry Senior Member. 0. 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 always put the Celotex under the slab to ensure that it doesn't deteriorate between laying it down and screeding. You also mentioned that there are vinyl tiles over the floor. You'll also need to take the dpm up the walls as well. 5kg multi chamber bags. . Unless there is an easy way. There’s also ridges from where the tiles used to be. Use 1000 gauge or thicker – ideal for this is the polyethylene use for the DPM under your concrete subfloor. 20 mm thickness should do it and im looking for the. This DPM is a ‘thick’ plastic sheet mostly 1000 – 1200 gauge polythene material. 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. 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. The surface should be of sufficient quality and. Country. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. The guidelines state that a damp proof membrane that is placed under the flooring should be around 1200 gauge and constructed of polyethene. The current recommendations for an effective damp proof membrane are that the ground should be constructed using screed with the damp proof membrane laid either on top or below that layer. Don't use a bitumen at all, you are correct eventually your screed will fail. 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. weberfloor DPM can be applied on to concrete or cement based screed surfaces with a. 300 dries very hard Bitumen is soft so not compatible. T ·Öà 4 ·Öò 8 ·Ñ• 2, Jun 15, 2007. It needs: 100mm or more of well compacted type 1 MOT, sufficient sand to blind, DPM, insulation, screed. 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. ) chrysotile (white) asbestos fibres. 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. The heating must be switched off at least 48 hours before and after application Bostik Screedmaster One Coat DPM and Bostik Screedmaster One Coat Accelerator are both solvent free products and are suitable for use in all project workHow-to video with step-by-step instruction on how to apply liquid damp proofing, priming and then self leveling. Liquid DPM for Walls. #1. sandwiched under the screed, were also common and usually in liquid form, e. Insulation will then go on top and the screed layer would go over the whole lot. Roger Kenworthy on 2021-08-13 17:59:40: Question:Durability: A befittingly developed floor screed will outlast the else modules of the building. . (See FeRFA Guidance Note No. New-build install: £50 to £75 per square metre. For a self-levelling screed a system such as Flowcrete UK’s Hydraseal would be used. 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. 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. sandwiched under the screed, were also common and usually in liquid form, e. The 'vapour barrier' attached to your underlay will only protect your floor from a slab reading 75% RH or less. Temporary protectionI had part of a 9" wall knocked down for a doorway. Air bricks are. The difficulty is getting the underneath concrete to have a flat surface at exactly the right level. 24 Jul 2009. Silicone mastic is the way to go. It is usual practice to lay vent pipe under concrete and dpm. CS Flooring. The guy doing it tried to compensate by using more adhesive and most of the wood has. heated levelling screeds. 22 August 2019 at 10:27AM. Yup so the plan is: Existing garage is concrete which is a 75mm lower than the current house level. Im surprised the floors lasted that long 300 will fail over bitumen everytime. Then prime the marked out area. Posted July 28, 2021. 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. It's a complete lack of knowledge on your floorlayers part or possibly just a carpet fitter trying his luck. The best example of insulated floor thickness is 100mm (insulation) + 60mm (screed) + 20mm (floor tiles+adhesive). 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. This allows for the full 5kg or just half to be mixed at once depending on the area to be covered. Give it a good wipe with a damp cloth and let it dry before you start. 11 Protection against heat, and BS 8204 Part 1 2003, Section 6. 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. hallbeck, Jan 26, 2010 #5. 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. Country. This allows for the full 5kg or just half to be mixed at once depending on the area to be covered. Tramex reading at the time of vinyl removal was 3-4+. link with wall DPCs to form an impervious barrier to prevent moisture reaching the interior of the dwelling. Country. Care must be taken to a) ensure there are no holes or tears in the sheet that could allow. you can then lay your celotex or similar then concrete then screed or dpm concrete insulation screed . 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. The Epoxy DPM 5kg is supplied in two 2. Which type of coating is chosen will depend on the intended use of the floor. The position would vary in accordance with proposed methods of construction. 5mt x 4mt rolls | £ 56. 14 assuming 0. At the junction of wall and floor the membrane overlaps the damp-proof course in the wall. I intend to consult BC but would like to educate myself before I speak with them Thanks in advance. It should accommodate 0mm to 5mm (or thereabouts) It will cover an area of 26m2 (4m x 6. Contractor wants to paint Sika Primer MD on top of the self leveling compound. Guide Underfloor heating A guide for house builders NF71 NHBC Guide to Underfloor Heating 2nd draft RH. 10 Feb 2020. CSC screeding was very efficient that they screeded our floor in under 4 hours (around 91sqm) with the help of the Mixamate. Maybe better to use a fibre based leveling compound instead, like Granfix Fibreflex 50 or similar. This barrier is intended to stop moisture passing from one to the other. It has had an extension about 50 years ago and that is the problem room as the flooring was laid without any DPM under the existing concrete floor, so there are some rising damp issues (I think). To remove this type of asbestos containing floor. Liquid DPM for Walls. Guidance on how to install insulation between a floor screed with Kingspan Kooltherm K103 Floorboard. . Labour costs. This will allow the screed to. First, divide the floor up. My DPM was these tiles that were bitumnned/black jacked to the floor. 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. not really, you said that you intended to use DPM under SLC, compound won't adhere to dpm and if will will install tiles to the SLC and it will crack your tiling will be spoiled, you can do SLC, next apply liquid DPM and install tiles to it- that's the way in my opinion. No need for double DPM. 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. 5-10mm thick. The vinyl that was laid bubbled up, so contractor removed it. In both cases the surface on which the dpm is laid needs to be as smooth as possible. 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. 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. 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. Suitable for use with underfloor heating and for encapsulating electric cable undertile heating systems. For unbonded and floating screeds, a DPM may be specified between the base slab and the screed. If the concrete in-fill is low, after patching the DPM, putting the screed on it will cause the centre of the DPM to drop and pull away at your new seal around its. However I'm pretty sure there is no damp proof membrane (or course?) as our water source, a large well, is under the floor and a couple of years ago it flooded into the dining room. hallbeck New Member. 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. screed (with UFH) 75mm. 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. Dig the oversite ground to whatever height allows your hardcore, insulation, blinding, slab,screed. 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 old adhesive should of been removed. Most damp-proof floor coatings are applied directly to the concrete floor surface using a brush or roller. Buy Now. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. Where a concrete slab or a screed is to be poured on top, the VCL will also protect the foil face of the board from alkalis within the concrete, and stop poured concrete opening board joints and causing a thermal break. Any existing floor screeds, coatings or adhesive residues. Gaz, you need to change your message setting as I can't reply. 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. heating installations with cementious screeds provided a temperature of 27°C is not exceeded. £12 - £16 per m2. studs 63mm x 38mm at maximum 600mm centres. Eventually I will rip out the old floor and replace it but I would like to understand (as much as possible) what is going on under it without taking it off. You should use them to protect all final floor finishes. if no dpm I would blackjack 2 coats on. This can only normally be guaranteed if its an new build or extension and most houses have been sold, inherited etc. Can you put DPM over screed? Liquid DPM is a system that is used over a base floor. Now we realise this cannot be done and are trying to get out of a fix. Yes run the dpm up the wall to connect wall dpc with floor dpm. UFH inside plastic polypanels 75mm screed (probably not liquid). Cement screed. 5m x 100m, 2m x 100m, and 2m x 50m. You now have a 'swimming. This is done to maintain energy efficiency and prevent. BS8203 recommends a maximum of 75% RH prior to the installation of sensitive finishes. The floor make up is compaced hard core, 125mm concrete, dpm, 100mm insulation, 75mm concrete screed ( polished and heated). 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. Cushion Ultra Silver Wood 10m² Underlay: The best laminate underlay for damp protection. TiT. 1314. Coverage: Approx 6 m at 3 mm thickness. either way, as the other posts say, you would be better screeding which will also take out any irregularities in the concrete. The floor make up is compaced hard core, 125mm concrete, dpm, 100mm insulation, 75mm concrete screed ( polished and heated). I have flowed screed planned for the finish rather than sand/cement. For the best results, we recommend leaving it to cure for 28 days. I'm not saying this is the best thing to use. 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). 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. . 20)Reinforced concrete floor. They can therefore be laid under the DPM (the DPM is still necessary to prevent. 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. It's joining onto the garage I'm converting so the whole floor is getting built up with polythene DPM,. Location. He also saw hairline cracks in the top layer of screed in places. Damp proof membranes (DPM) A DPM should be a minimum thickness of 1200g polythene and linked to the DPC with a minimum 100mm overlap.