If under the screed this is normally a polythene dpm so the screed is then an. Insulation must be provided under their entire area to ensure compliance with the Building Regulations is achieved. To remove the screed in order to relay a DPM is, in most cases, completely unrealistic and actually completely unnecessary. 1200g dpm. 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. Property is mid 1960s, solid ground floor. The specific liquid DPM system will depend on the type of substrate or screed. 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. blocking/nogging for support of plasterboard 43mm x 38mm. 100mm c35 concrete with mesh. My house has a solid screed floor throughout the downstairs, with a Damp proof membrane about 100mm down. The guy doing it tried to compensate by using more adhesive and most of the wood has. The clips only pierce the thinner layer above the insulation, which is only really there to ensure an unbonded concrete/screed above. The DPM should: have sealed laps of at least 300mm wide. A Vapour Control Layer, or VCL for short, is a plastic layer that restricts the movement of warm, moist air from inside a property into the fabric of the building. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. The screed has water anyway, so a bit of ingress isnt an issue. so FBall seems the way to go). However the tiler should apply a Primer before screeding such as StopGap P141. #7. Warm construction build-up would be: - Sand blinded sub-base. It also looks like there could be polystyrene under the screed, this will be a barrier to damp coming from the ground. Notch7. If you're laying Karndean over existing flooring, be sure it is properly prepared. 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. Diagram B38 - DPM lapping under DPC for thickness of inner leaf. Alan Jackson - Commercial Manager UK and Ireland - Gypsol. Small hole dug through 2" soft sandy concrete to reveal hardcore and soil. It is advisable to have a minimum of 100mm insulation covered with 60-80mm screed. 8 Apr 2013. com Do I need a DPM under laminate flooring? Simply put yes. Vac up any loose sand once it's set and then tile. The tiler can then latex or screed over the DPM. No need for double DPM. I intend to consult BC but would like to educate myself before I speak with them Thanks in advance. Which type of coating is chosen will depend on the intended use of the floor. Note though that this will raise the floor level by 75-100mm (depending on the insulation). Developed to suppress residual construction moisture in cementitious subfloors including power floated concrete and sand/cement screeds. A hydronic setup is connected to your central heating system, powered by a boiler or some form of renewable tech (eg a heat pump). Checkatrade offers the following guide: Electric underfloor heating cost. 34 dpm under insulation and screed. Will prim t be okay as primer on top of turbo? Thanks PeteUnless designed otherwise, the minimum specification for all partitions should be: sill and head plates 63mm x 38mm. 5mt x 4mt rolls | £ 56. This can include timber floors, tiles, laminate flooring and carpet. When sand-blinded, BAL DPM allows tiling onto difficult substrates such as steel. The same larger hole after I cut back some of the sandy concrete. For unbonded and floating screeds, a DPM may be specified between the base slab and the screed. 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. Unbonded screeds are used either to install a damp proof membrane (dpm) between the base slab and the screed or where the base slab surface is unsuitable for a bonded screed due to problems such. Since that period I've take out the bitumen screed/dpm and been on the concrete slab since about mid February/March. Country. . 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. Get it level then when it is dry and can screw through floor board into blocks. blocking/nogging for support of plasterboard 43mm x 38mm. If you are installing where existing floors have been removed, check that there are no traces of previous adhesive residue. 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. heating installations with cementious screeds provided a temperature of 27°C is not exceeded. The liquid membrane forms a strong seal and makes a permeable layer to enable moisture to evaporate off. by sound of it you could latex that floor 3x with the amount of screed you intend buying and you can't prime under a dpm or dpm over a water based screed. Non-structural floor screeds shall be adequate for the location and intended use, and provide a suitable background for floor finishes. The advice of a structural engineer should be sought for any exceptional point loads in the design of the floor. This should be laid on a bedding material such as screed which doesn’t damage the sheet and has fully sealed joints. Depends where the UFH pipes are. Country. Ideal for use where there is no functioning structural DPM (common in older properties). Registered Office: 6 Acre Close, Rustington, West Sussex BN16 3PG. TiT. Step 3: Lay the watertight membrane. As a waterproofer, BAL DPM is an easy two-coat system when used with BAL Self-Adhesives Butyl Tape in corners and junctions. If you noticed the buildup wording is different to the detail drawing, it clearly shows dpm on top of concrete. 4 Apr 2017. 67. I am the Managing Director of the Multi-Award Winning Speed Screed. #3. My query is regarding the floor insulation, damp proofing and screed. 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 Carpetright), there are certain BS you must follow for correctly preparing a sub. I am putting down a 22mm engineered oak floor so will use an underlay without a dpm. It's a complete lack of knowledge on your floorlayers part or possibly just a carpet fitter trying his luck. Then the lamiante has trapped this water in creating the sweat. Then a DPM on top to avoid them floating in the screed. 75m2 at 3mm, 1. 12 Sep 2015. Visqueen EcoMembrane DPM. The concrete slab was usually 100 to 125mm thick. 100mm thick (can be heated) - Levelling screed (as required: self levelling compound, sand/cement screed etc) - Flooring, e. Remove and Smooth. I will post up a pic of the failed LVT in a minute for you! Screed seems to be getting damper. 21 Sep 2016. DPM (1200 gauge visqueen) Old Concrete Slab. Reinforcing concrete. DPM is usually below the concrete, then the insulation, then a polythene sheet to stop the insulation floating as the screed is poured. For this, a metal mesh standing with plastic pillars ( (feet) will be laid before the concrete is. Made from recycled materials. 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. Use polyethylene sheeting to create a waterproof membrane to ensure that there is no leakage of the screed when it is pumped in wet. For technical support please call. Fax: 0800 270 7368. AFAIK - PIR insulation boards need have a DPM under them to protect the board. 0. Put an upstand of 25mm celotex around the perimeter of the room and a dpm under the concrete lapped up the walls, being higher than the dpc won’t matter Jimmycloutnail, Jan 23, 2019 #4. The dpm is extended and taped around this opening. This site contains a wealth of information on our extensive product range, along with a selection of videos demonstrating their application. 2: Fill the gaps with concrete, lay a DPM over it, insulation, then a concrete / fibre screed. Ltd. However the chance that the floor tiles or adhesive can release fibres and become respirable when disturbed is very low. 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. 5kg multi chamber bags. water will be likely to collect between the DPM and the old 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. hot bitumen, or cold bitumen in solution. The position would vary in. co. 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. This generally takes 1-2 days, depending on the thickness of the floor screed. 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. As with the Kooltherm installation, start by ensuring a clean and level surface. Many can be used over a variety of existing uneven substrates, using gravity to allow the latex mixture to self-level. If you don't allow the screed to dry properly, the moisture will be trapped within the screed potentially causing failure. You must design out the (damp/thermal) vulnerabilities associated with raft type foundations as they can be a headache. The mat will get glued down to the screeded UFH, and then the. Packaging: 25kg bags. Maybe better to use a fibre based leveling compound instead, like Granfix Fibreflex 50 or similar. Ground-bearing concrete floor slabs should be protected against ground moisture by providing a continuous damp proof membrane (DPM). The screed manufacturer agrees that their screed can receive an epoxy DPM. 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. Issues to be taken into account include: installation. Needs a dpm under it and i normally put one on top too - stops you accidentally sticking the boards to the insulation. Suitable for most construction damp proofing requirements. The damp proof membrane (DPM), normally 1200g polythene or radon barrier, should be laid over the blinding,So not convinced glue down is right. The current pipes to it will be diverted to another drain to the left of the photo. you can then lay your celotex or similar then concrete then screed or dpm concrete insulation screed . There will be a damp-proof membrane under the insulation and possibly a second membrane on top, depending on the type of screed. Water is added to ensure a thorough mix and to aid workability. 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. What should normally happen is the inner course should be removed to concrete slab level. 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. 3) 50mm - Screed with Concrete Fibres, on top of the insulation boards. The DPM (Damp Proof Membrane) is laid under the insulation on top of a soft blinding to ensure it is not punctured. Use a thick bed adhesive unless your competent to use screed, it takes skill and practice to create a flat floor. Cushion Ultra Silver Wood 10m² Underlay: The best laminate underlay for damp protection. Aug 18, 2010. 18) Bricks. Mapeproof One Coat can be used with underfloor heating systems providing the system has been fully commissioned as per BS8203 2009, Section 3, 3. 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. sandwiched under the screed, were also common and usually in liquid form, e. 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. Capital Valley Plastics Ltd Damp-Proof Membrane Black 1200ga 25m x 4m (47163) (55) compare. 300 dries very hard Bitumen is soft so not compatible. i'm you have gathered by now, you havn't left enough depth to do this. Mapeproof One Coat is not recommended for heated subfloors where wood floor coverings are to be installed. Polycote DPM Primer is a superb twin pack high-performance epoxy coating that. Our quarry tiles were pretty much laid on dirt so there were some big variations in height over the whole kitchen. 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. Find. Damp Proof Membranes. Country. AN INTRODUCTION TO. Non-structural floor screeds shall be adequate for the location and intended use, and provide a suitable background for floor finishes. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. For guidance on using DPM One Coat Membrane with screed products refer to the individual ScreedPro Data sheet concerned. 14) Screed. £12 - £16 per m2. Apply sand-blind base (this base should be level to within 5mm along any 3m straight edge). The best example of insulated floor thickness is 100mm (insulation) + 60mm (screed) + 20mm (floor tiles+adhesive). When stripping the bathroom, the area under the bath tub was bare concrete, lower than the rest of the "black" floor throughout the property. 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. 22) Steel. is that do-able? if so, can I just run the DPM 1 course above DPC? it's too late to tuck. You adjust the concrete slab to let your. e. insulation 60mm. Also, even with 80mm screed directly over Celotex the sab can feel a bit "hollow". I would think a strip out and start again would be your best option, you should consider where/why there is water evident before. The old adhesive should of been removed. Pumped anhydrite floor screeds are not much dearer than ready-mix sand/cement, costing around £25/m3 (laid to a 50mm depth). Also there MUSt be a DPM under the screed to stop any substrate moisture coming up from underneath as a result of heating. 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. UZIN has the right floor damp proof membranes for damp proofing floors. Perhaps you could paint a liquid DPM band all the way around the bottom, or flash band skirt, stapled on to the framework, tucked under the cladding. PermaSEAL Liquid DPM can also be applied to concrete floors below screeds. Mot1 Sand/hardcore sub base. 4 so you have around 1. The old floor tiles do contain a small amount of asbestos ( Marley tiles etc. indd 2 08/08/2016 16:50:21DPM underneath and a plastic sheet on top to stop the screed getting between the insulation panels. 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. Under Floor Heating; Screed Care; Testing; Tips; Blog; Contact; A Practical Guide to Screed Testing: What Do the Experts Say? Download. it could easily be up and down by up to 15mm. 11 Protection against heat, and BS 8204 Part 1 2003, Section 6. Hull. Posted July 28, 2021. Was looking to do liquid DPM sandwich with fball 1200/F77/1200 (or NA/1cDPM/NA but that’s costing another 30% more. 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. Country. 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. It's joining onto the garage I'm converting so the whole floor is getting built up with polythene DPM,. Perfect for new builds and refurbishment projects, our range of floor insulation products include optimum peformance OPTIM-R Vacuum Insulation Panels (VIPs) with an insulating performance up to five times better than commonly used insulation materials, and. Unbonded Sand and Cement Screed Minimum Thicknesshelppppppppppppppppppppppppp just had to quote for screed flooring. Effectively, a damp proof membrane (DPM) is used to create a barrier between a concrete (or screed) subfloor and a wood floor. The liquid membrane forms a strong seal and makes a permeable layer to enable moisture to evaporate off. Can you put DPM over screed? Liquid DPM is a system that is used over a base floor. So, as money's too tight to mention round here, I replaced the leaking door with a cheap UPVc one. If DPM ok then. There’s also ridges from where the tiles used to be. T ·Öà 4 ·Öò 8 ·Ñ• 2, Jun 15, 2007. The difficulty is getting the underneath concrete to have a flat surface at exactly the right level. 75mm pir but we have decided on 100. rip some 18mm ply. adamhardy Member. The DPM we use does not cancel all moisture out as this will end up. It may be applied onto either a solid in-situ concrete ground floor slab or onto a precast concrete floor unit. We used the Ultra Floor system, Ultra DPM-it,. 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. Water under tiles. Block and beam grout/slurry wetness. flooringman, Apr 7,. of the screed should be checked by the Main Contractor. DPMs on top of the slab, i. 1 Feb 2010. #2. Temporary protectionI had part of a 9" wall knocked down for a doorway. Applying Damp Proof Membranes. . 5m) It will have 50mm insulation boards on top of it, followed by 18mm/22mm. DPM's must be carefully protected where folded up the perimeter walls, and lapped under the DPC particularly at door openings. 11. •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. #1. LKAB Minerals +44 (0) 7966 651006. 1 left. Fig. Deleted member 25896, Feb 2, 2021 #5. 5m2 at 1mm thickness 1. Covering it in denso tape and maybe putting some dpm over the top before screeding? Yes copper is best and lasts forever, but in this situation what would you do? So far I'm leaving towards plastic which makes like easier, less stress thinking that there are all those copper joints under the screed and underfloor heating. This allows for the full 5kg or just half to be mixed at once depending on the area to be covered. DAMP PROOF MEMBRANE. sandwiched under the screed, were also common and usually in liquid form, e. Coverage: Approx 6 m at 3 mm thickness. These black DPMs can also be used with underfloor heating - under normal operating conditions this will not adversely affect the membrane. Option 1 is clearly cheaper but as long as it takes a screed floor (says it does) and gets signed off by. At its deepest it’s 150mm, what I’m stuck with is the builders trying to push on with the job. However to get BC off your back you can use a epoxy DPM and sand scatter it before it sets. 1200g DPM will be fine. Two coats will provide protection up to a maximum hygrometer reading of 95% RH. 10 Sep 2021. I have flowed screed planned for the finish rather than sand/cement. 0113 2455450 sales@rawlinspaints. What is liquid DPM? Liquid DPM is a system that is used. This DPM is a ‘thick’ plastic sheet mostly 1000 – 1200 gauge polythene material. 100 hardcore, 50mm builder's sand to blind, 1200 gauge DPM, 70mm insulation (Celotex, Kingspan, etc. dthobhani; 18 Mar 2011; Floors, Stairs and Lofts; Replies 2 Views 1K. 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. PermaSEAL Liquid DPM can also be applied to concrete floors below screeds. Now we realise this cannot be done and are trying to get out of a fix. 55mm of TS15 will impart around 1. For unbonded and floating screeds, a DPM may be specified between the base slab and the screed. Which is supposed to be a DPM equivalent. It is black/blue in colour and comes in conveniently multi-folded rolls. 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. #1. You are therefore at the edge of the joists capability. The DPM (Damp Proof Membrane) is laid under the insulation on top of a soft blinding to ensure it is not punctured. Mastic Asphalt – this is the earliest form of liquid DPM and is usually laid on the top of another membrane or a fibreglass surface. Staffordshire. P. To avoid such issues, it is therefore extremely important to make sure that the screeds are given sufficient time for drying. Epoxy DPM itself (the actual product epoxy) wont fail once set. There is a small section along the chimney where. Then use the correct screed. However, when I hammer-fix the battens to the concrete I'm going to punch holes in my DPM. CS Flooring. "Turn off electricity and gas only if it’s safe to do so," he said. Magnesite must be completely removed. . (DPM) with joints well lapped and folded. 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. On the other hand, a dpm on top of the new concrete will push all the moisture towards the walls, so you would have to incorporate the dpm into. weberfloor DPM can be applied on to concrete or cement based screed surfaces with a. SikaBond® Rapid DPM is a single part moisture curing polyurethane. Thanks for reading. The vinyl that was laid bubbled up, so contractor removed it. Price: £4. if your DPM were above the concrete, the uFH would be heating a large damp lump of concrete. Damp proof membranes (DPM) A DPM should be a minimum thickness of 1200g polythene and linked to the DPC with a minimum 100mm overlap. Visqueen are recommending we don't use Ecomembrane but instead use Visqueen Vapour Barrier if we have a DPM under a screed with UFH heating, because it doesn't have folds in it and this helps prevent cracks in the screed. 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. It offers thermal conductivities as low as 0. The dpm is still continuous but laid down in the trough to maintain damp proofing. Jan 24, 2019. But if you’re on a tight schedule, allow at least 7 days before applying your vinyl floor covering. We have our own in-house delivery fleet of FORS Gold vehicles with Moffett mechanical off-loads delivering nationwide. UFH Pipwork. 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. I want to level my workshop floor. 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. Laying new floor - needs DPM? dunroving Posts: 1,881 Forumite. Two coats will provide protection up to a maximum hygrometer reading of 95% RH. As a rough guide, laying conventional screed costs around £15/m2, increasing by around £5/m2 when delivered ready-mixed. carpet, tiles etc. Can anyone advise me if this needs to be completely dried out before put the screed down? I have exposed part of the slab by removing th insulation and peeling back the upper dpm and this has slowly drie over the week but the dpm is keeping the wet in where its stil. 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. 24 Jul 2009. DPM is normally used in floors. Changed mate!constructed as a separate concrete (Figure 2) or concrete masonry (Figure 3) perimeter foundation wall with the slab laid later. The ground floor is wooden floor boards and there are 2 rooms I need to do. He also saw hairline cracks in the top layer of screed in places. Our costs are ballpark averages – get a local tradesperson to quote now. It is essential that this. Laying new floor - needs DPM? dunroving Posts: 1,881 Forumite. hot bitumen, or cold bitumen in solution. Concrete & Sand/Cement Screeds Concrete and sand/cement screeds must be dry and any laitance or surface treatments removed. 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. As a rough guide, laying a conventional sand/cement screed costs around £15/m2, increasing by around £5/m2 when delivered ready-mixed. 8). 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. 21) Timber block. All other sheet membranes can be used with unbonded toppings. Air bricks are. Alan Jackson - Commercial Manager UK and Ireland - Gypsol. Pro-Screed Gold is suitable for application over most underfloor heating systems. 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. LAY DAMP PROOF MEMBRANE. 3. 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. Thin screed to level old concrete floor. Checkatrade offers the following guide: Electric underfloor heating cost. In addition to the damp proof membrane (normally a 1200-gauge polythene sheet below the insulation), a 500-gauge polythene VCL. Hence we always say DONT apply a surface dpm to a subfloor subject to rising damp. Then mix up the high performance stuff as that is fibred and can be taken to a feather edge. DPM sheets should be overlapped by at least 300mm. 8 Can you put DPM under. 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. 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. 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 specific liquid DPM system will depend on the type of substrate or screed. The tiler can then latex or screed over the DPM. If the coating is not going to be the final decorative surface and. The purpose of DPM. 50 Ex VAT £21. Pre screeding, you lay the DPM, install the insulation sheets and create vertical upstands of insulation block around the outside perimeter of the wall. Visqueen ECO Membrane Data Sheet. 16 Nov 2016. com. Replacing over half of your floor will mean you’ll have to insulate to at least 0. the cut. As an alternative to under concrete or surface damp-proof membranes a damp-proof membrane may be sandwiched between the site concrete and the floor screed, as illustrated in Fig. . com. Renovation property: £135 to £185 per square metre. 1: Fill the gaps with concrete and get an asphalt company to lay an asphalt screed over it to restore the DPM. Floor screed PIR cavity board Lay, level and compact the hardcore in layers (usually 150mm min / 250mm max). #2. 5sqm has blown. concrete slab. #3. Cement screed. POLYTHENE DPM & VAPOUR BARRIERS. 9. 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. #1. 50 /sqm. He intended to stick the floor to the bitumen DPM. First, divide the floor up. £51. 9% screeds been down since February. Ideally there should be a fully working dpm under the main concrete slab but where this does not exist or where the time for the slab to dry out sufficiently is longer than the building programme can permit, a dpm can be included either above or below the screed. Solid floor insulation –screed finish: Per m 2: £70: £90: £80: Labour: Per day: £180: £250: £215:. Any advance on laying 75mm kingspan directly on existing screed with DPM beneath, then laying 18mm T&G moisture resistant chipboard. - Polythene membrane (DPM) - Insulation (rigid board type) - Concrete slab min. Well, when I did exactly this on my lower retaining wall - a mere footandahalf high - I lined the back with DPM, the stuff you put under screed to seal yer floors from rising damp. The polythene damp proof membrane (DPM) – generally a 1200 gauge- can now be rolled out into place ensuring the perimeter abutments are adequately covered. 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. 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. 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. CSC screeding was very efficient that they screeded our floor in under 4 hours (around 91sqm) with the help of the Mixamate. 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. This seems to have been used in abundance before the original screed was put down. you need to dig up the old concrete then lay a couple inches of sharp sand. No this is designed to be used under floor screeds, tiles, render or plaster. I always put the Celotex under the slab to ensure that it doesn't deteriorate between laying it down and screeding. phatboy. Ultraplan Renovation Screed 3240 is suitable where good resistance to loads is required, also for castor wheel traffic and underfloor and undertile heating systems. 3. Applying Damp Proof Membranes.