The damp proof membrane (DPM), normally 1200g polythene or radon barrier, should be laid over the blinding,So not convinced glue down is right. Note though that this will raise the floor level by 75-100mm (depending on the insulation). Other benefits. 19 Mar 2011. I am the Managing Director of the Multi-Award Winning Speed Screed. e. studs 63mm x 38mm at maximum 600mm centres. This can include timber floors, tiles, laminate flooring and carpet. Alan Jackson - Commercial Manager UK and Ireland - Gypsol. jeds. 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. An expansion gap may be necessary around the edge of the floor finish in screed or. It is good practice to either fit another DPM or tape the insulation joints, when adding a screed on top of inso'. The purpose of DPM. It should be waterproof to prevent any rising damp getting through. 100m² per roll. For technical support please call. Energy Efficiency: Concrete floors generally possesses lofty thermal mass & this may be. Mastic Asphalt – this is the earliest form of liquid DPM and is usually laid on the top of another membrane or a fibreglass surface. 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. blake floyds; 23 Jul 2009; Building; Replies 3 Views 5K. Under ambient conditions, PALACE 1-COAT DPM is ready to receive a smoothing compound as soon as 4 - 5 hours after application. . 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. 1314. Temporary protectionI had part of a 9" wall knocked down for a doorway. Liquid DPM for Walls. 20 mm thickness should do it and im looking for the. 21 Sep 2016. I could put the dpm under the concrete which would be as effective. I'm not saying this is the best thing to use. Small hole dug through 2" soft sandy concrete to reveal hardcore and soil. Damp proof membranes (DPM) A DPM should be a minimum thickness of 1200g polythene and linked to the DPC with a minimum 100mm overlap. Fibreglass 1. In both cases the surface on which the dpm is laid needs to be as smooth as possible. Remove and Smooth. We've just had our garage converted and our builders have laid a screed floor. Block and beam grout/slurry wetness. Step 3: Lay the watertight membrane. 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. You will need to tear the lot up. You can usually achieve this with at least 100mm of good quality foam insulation or 150mm of mineral wool insulation, but this figure will vary depending on the make-up and size of your. 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. 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). To avoid such issues, it is therefore extremely important to make sure that the screeds are given sufficient time for drying. Top. #1. AN INTRODUCTION TO. 4 Screed. Damp Proof Membranes. We have our own in-house delivery fleet of FORS Gold vehicles with Moffett mechanical off-loads delivering nationwide. 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. 5kg multi chamber bags. screed. Resin and cementitious floor finishes combining performance and design. #Screeding #Sc. 25W/m 2 K to meet with building regulations, even if you didn’t plan to. Ideal for use where there is no functioning structural DPM (common in older properties). I think this is too expensive, so got a quote of another supplier of £2565 plus any potential floor preparation, with latex screen costing £13 /sqm or a feather finish at £2. user contributions licensed under CC BY-SA. Proposed floor is pitch pine boards secret-nailed to 2 x 2 inch battens with insulation between, onto a concrete floor not known to have a DPM under it; therefore, DPM to go under the battens. 24 h After curing of screedSANS 10400, Part J Floors (which is the SABS “deemed to satisfy” regs) states: “Ventilation of the subfloor space in suspended ground floors shall be provided by means of openings spaced not more than 2,4. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn,. rip some 18mm ply. The builder wants to apply a DPM to the top of the slab before it is dry. 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. or as a sandwich membrane in base concrete or between the base concrete and screed. 5 ratio of cement to sharp sand. We have a few options: 1. Curing Under Polythene 12 hrs 12 hrs Drying Time To Receive Finishes - from removal of curing polythene sheet 50mm thickness and 50% RH. 75m2 at 3mm, 1. Mark El-Kadhi New Member. 2) 25mm - Celotex TB3000 Insulation Board. Its an easy job to do yourself - also check Seconds & Co for PIR. This allows for the full 5kg or just half to be mixed at once depending on the area to be covered. DPMs on top of the slab, i. com Do I need a DPM under laminate flooring? Simply put yes. 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. if your DPM were above the concrete, the uFH would be heating a large damp lump of concrete. Let’s hope you have a good water table as that’s the wrong dpm used. SikaBond® Rapid DPM is a single part moisture curing polyurethane. 100mm thick (can be heated) - Levelling screed (as required: self levelling compound, sand/cement screed etc) - Flooring, e. CS Flooring. 10 Sep 2021. B. Normally you would put a compacted bed of about 50mm sand under the DPM. Self levelling compound is often known as floor screed or floor levelling compound and is essential for creating an even floor surface in preparation for upper flooring layers. The dpm needs to be clean and dry. Request a callback. 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. heated levelling screeds. Reaction score. JB Flooring Well-Known Member. Ideal for use where there is no functioning structural DPM (common in older properties). insulation 60mm. He has sealed the joints as well so hopefully they won't squeak. 4,049. Self levelling compound was laid straight on top of the concrete floor (with no primer). If you're laying Karndean over existing flooring, be sure it is properly prepared. It is advisable to have a minimum of 100mm insulation covered with 60-80mm screed. Damp proof membranes (DPMs) can be used to help resolve damp issues which already exist or to avoid damp or moisture problems in. Issues to be taken into account include: installation. 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. ; Stiffness: Concrete floors generally possesses adequate prudery & does not parry under the applied load which result in generating problems in non-structural elements, e. 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. Hi, I'm doing a kitchen modernisation in my ex-Council house which was built in 1947. Our Liquid DPM can be used on walls under a render to create a flexible waterproof layer. 11. 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. Assuming that the damp proof membrane (dpm) under the concrete has failed in areas then yes you possibly would get the odd patch of dampness showing in the floor. A poorly compacted, damaged or weak screed should be completely removed by mechanical means and reinstalled correctly. Once set, you can then apply your screed flooring to the DPM. celotex goes UNDER concrete. It stops around 10mm away from the internal walls in all rooms. It is better to put the insulation under the concrete (which wants to be 100. The subfloor. Visqueen EcoMembrane DPM. Pumped Anhydrite Screeds. Drybase Liquid-Applied DPM should be used in situations where the final surface is going to be covered. Visqueen High Performance Damp Proof Membrane. 4. We converted our garage and building control are insisting I install a DPM over the screed (even though the DPM runs under the concrete raft foundation of the house). The specific liquid DPM system will depend on the type of substrate or screed. Side extension refurb: old concrete slab is uneven with a line of about 10mm difference in heights down middle, and dpm under screed is visibly not 100%, with a few gaps. At its deepest it’s 150mm, what I’m stuck with is the builders trying to push on with the job. For unbonded and floating screeds, a DPM may be specified between the base slab and the screed. Visqueen 2000 gauge Polythene - 12. Silicone mastic is the way to go. 3k. Mot1 Sand/hardcore sub base. Hello, I have noticed some funny things going on under the floor of our recently bought house, which was originally built in 1905. #5. As a rough guide, laying conventional screed costs around £15/m2, increasing by around £5/m2 when delivered ready-mixed. Developed to suppress residual construction moisture in cementitious subfloors including power floated concrete and sand/cement screeds. This self leveling concrete’s use of latex. Misinformed on this as he had put a dpm under the chipboard. If modified screed is used you can get down to 55mm. I intend to consult BC but would like to educate myself before I speak with them Thanks in advance. So, as money's too tight to mention round here, I replaced the leaking door with a cheap UPVc one. Would a liquid dpm work,in past I had similar problem, I've just poured some liquid dpm in to the hole & help it with a trowel to find it's way under the concrete,seem to work as I never had damp issue when I moved indoor stop cock to new position at previous place & here when I laid new pipe under utilty floor after clay pipe failed, 10 years on, not. For traditional screed, the usual total will fall within the range £18. 100mm **concrete base*. 1 left. 5sqm has blown. Any advance on laying 75mm kingspan directly on existing screed with DPM beneath, then laying 18mm T&G moisture resistant chipboard. 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. Customer asked me how did they stop rising damp before the Dpm sheet was used and it made me think ( that hurt ) . apparently some of the screeds had a cold or hot bitumen in or under them. Jan 24, 2019. Bring the membrane up the surrounding foundation walls until it is just high enough to connect with or form the wall damp proof course. £14 per m2. It also looks like there could be polystyrene under the screed, this will be a barrier to damp coming from the ground. I think underfloor heating would work if you layed DPM, insulation (as much as poss) woodchip flooring and don't use a screed. I am assuming its asphalt with a bitumen top layer, 10-15mm thick. I will be tiling over the screed so looking for the simplest option. On a job that’s had anhydrite screed pumped in, using a Wolff gm200 moisture meter readings in parts are 99. I moved into my new build nearly 2 months ago now and am having quite a few issues. adamhardy Member. 15) DPM under screed. Am hoping for UFH in screed (supplied won't do 50mm, only 65mm). Laybond Screedmaster One Coat Liquid DPM 2 part solvent free epoxy surface damp proof membrane developed to. We have our sub concrete floor in, and there will be a 1200g dpm, then 100mm insulation, then another dpm and finally 65-70mm screed. Firstly, there was no need to use a liquid dpm if you used underlay with a built in vapour barrier. weberfloor DPM is a two-component epoxy based chemical damp proof membrane that is capable of being applied in one coat, dependent upon the condition of the substrate and quality of workmanship to ensure full coverage is achieved at the required thickness. #1. 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. 3. will come down and meet the insulation under the screed so the screed is totally floating. DPM over a new underfloor heated screed, the heating system must be turned off 48 hours before application. 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. If DPM ok then. (See FeRFA Guidance Note No. Screed & Insulation. For an excellent balance of. Guarantees the early laying of all floorcoverings. 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. 1200g dpm. DPM, Celotex, 1000 gauge poly, 100-150mm concrete with or without reinforcement, 50-80mm screed. The DPM should come up in an upstand and tie into the DPC on the. 5mm Polyflor . The total floor insulation cost will have two elements – the cost of materials and. The engineer (who is a bit belt and braces) recommended a block and beam floor supported by new foundations so as not to add extra load to the existing 1930s foundations. 45sqm to supply and fit. Modified anhydrite screeds for use with UFH can now be installed as little as 35 mm deep with a 15 mm pipe in a domestic application. Floor under carpet marked with chalk for wet areas. 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. Depends where the UFH pipes are. Care must be taken to a) ensure there are no holes or tears in the sheet that could allow. Liquid DPM for Walls. A DPM should be impermeable to water in liquid or vapour form and should be tough enough to withstand possible damage during laying of screeds, concretes or floor finishes. A full sheet DPM is 250 microns (1000 gauge) thickness or above. Walkable in 6 hours. 21) Timber block. Pro-Screed Gold is suitable for application over most underfloor heating systems. DPM is usually below the concrete, then the insulation, then a polythene sheet to stop the insulation floating as the screed is poured. No this is designed to be used under floor screeds, tiles, render or plaster. Property is mid 1960s, solid ground floor. 3. Information ARDEX DPM 1 C. The mat will get glued down to the screeded UFH, and then the. They can feel wobbly when you walk on them but you get to the point when you can't get them any better and each give you walk on them or lift them you end up going around in circles. screed thickness. £51. With the number of planning applications for basement extensions rising by 183% according to research by Halifax, tilers need to be. . 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. For example, when installing Celotex under floor. The clips only pierce the thinner layer above the insulation, which is only really there to ensure an unbonded concrete/screed above. BBA certified - third party accreditation. My question is thoughts on floor layout. I will post up a pic of the failed LVT in a minute for you! Screed seems to be getting damper. Our expert team are ready to offer you the very best solution for waterproofing. 2. 22 August 2019 at 10:27AM. Out of the 7sqm of floor i guess about 1. All other sheet membranes can be used with unbonded toppings. Performance can be significantly affected if the liquid DPM does not adhere to the base layer properly, therefore careful preparation must be done to make sure that the receiving surface is level and free from debris. Can you put DPM over screed? Liquid DPM is a system that is used over a base floor. The DPM should: have sealed laps of at least 300mm wide. com. Fax: 0800 270 7368. 65mm Screed. Use polyethylene sheeting to create a waterproof membrane to ensure that there is no leakage of the screed when it is pumped in wet. It will - I believe - deteriorate with UV light, but that won't apply to anything cover by the soil itself. 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. The plan was to lay American Black Walnut but the hallway floor was not level. Therfore putting foil faced boards under screed is a waste of time and is the principle reason kingspan make tissue faced boards. 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. 50mm C&S (1:4) screed towelled smooth. All other sheet membranes can be used with unbonded toppings. 16) Concrete slab 300mm. An ARDEX Damp Proof Membrane will protect the floorcovering. This essentially means that the screed has been laid in direct contact against the bottom of the aluminium door frame. 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. 250mu (1000G) Black Polythene Damp Proof Membrane (DPM) 4m x 25m (100m2/Roll) URN: 5004075. 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. A traditional sand and cement screed is normally a 1:4 or a 1:3. This process is not 100% foolproof and so during screeding an extra pair of hands is useful to tuck the materials together until the weight of the. Moisture in the base will impede the drying of the screed. The floor make up is compaced hard core, 125mm concrete, dpm, 100mm insulation, 75mm concrete screed ( polished and heated). My work will be (in order of layers): 1) DPM 1000 gauge with joints taped with Polythene joint tape. you then have a continuous damp couse not inportant if concrete above dpc level. Use screed on top of a concrete base to give your floor a level and smooth finish. 4. Renovation property: £60 to £85 per square metre. Depends where the UFH pipes are. This told us tha. DAMP PROOF MEMBRANE. This allows for the full 5kg or just half to be mixed at once depending on the area to be covered. . 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. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. 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. Complete range, complete solution. I see some under the wood bearers, so hopefully this will keep the base dry. . #2. rogerk101 likes this. 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. 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. Guidance on how to install insulation between a floor screed with Kingspan Kooltherm K103 Floorboard. rev 2023. The basic screed construction for under floor heating systems generally follows the ‘floating’ screed construction, where a Damp Proof Membrane (DPM) and tacker insulation panels are laid over the. 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. 1200g DPM will be fine. 28 Sandiwch damp-proof membrane. 29 per m², £42. 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. Screeds are covered by BS 8204, Screeds, bases and in-situ floorings, (2004). Fast drying screed cost. 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). Get it level then when it is dry and can screw through floor board into blocks. Maybe better to use a fibre based leveling compound instead, like Granfix Fibreflex 50 or similar. 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. Cushion Ultra Silver Wood 10m² Underlay: The best laminate underlay for damp protection. To remove the screed in order to relay a DPM is, in most cases, completely unrealistic and actually completely unnecessary. The DPM should: have sealed laps of at least 300mm wide link with wall DPCs to form an impervious barrier to. 2 Feb 2010. The screed manufacturer agrees that their screed can receive an epoxy DPM. 1955 house, recently moved in and presuming no DPM under concrete slab. Then once the screed is dry use a liquid DPM such as F-Ball Stopgap F77. 20)Reinforced concrete floor. DPM is usually below the concrete, then the insulation, then a polythene sheet. WoodYouLike. When stripping the bathroom, the area under the bath tub was bare concrete, lower than the rest of the "black" floor throughout the property. 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. 21. Visqueen ECO Membrane Data Sheet. Nice. 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. Ground-bearing concrete floor slabs should be protected against ground moisture by providing a continuous damp proof membrane (DPM). 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. A few months have passed since then and is now on average 2. First, divide the floor up. Said he'd provide a quote but didn't come back to me. It is a thermally effective solution that is equally efficient in concrete floors, beam and block floors, and suspended timber floors. water will be likely to collect between the DPM and the old floor. 74 inc. Our Liquid DPM can be used on walls under a render to create a flexible waterproof layer. M. Many can be used over a variety of existing uneven substrates, using gravity to allow the latex mixture to self-level. Should I lap DPM under or over Dpc then celotex, then another DPM lapped up the wall with 25mm up stands. 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. Then prime the marked out area. There are two main options: 1. The specific liquid DPM system will depend on the type of substrate or screed. Insulate under the floor using the crawl space underneath. 00. Plastic DPM under slab everytime. Also, even with 80mm screed directly over Celotex the sab can feel a bit "hollow". You are talking about a solid concrete floor which has to be on load bearing stable ground. 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. e. (DPM) between the concrete and screed. Country. do I still need a DPM under that insulation? it is internal and sitting on a structural slab that is wrapped in DPM externally. 22 August 2019 at 10:27AM. 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. 6. 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. "Turn off electricity and gas only if it’s safe to do so," he said. ), then 500 gauge plastic (or just use the leftover 1200 gauge DPM) then 100mm concrete slab. To ensure a level finish to the floor, a layer of screed is added over the top of the concrete, which consists of sand and cement. Warm construction build-up would be: - Sand blinded sub-base. hallbeck, Jan 26, 2010 #5. It has excellent adhesion to. Ball and Co. 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. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. 034 W/mK, and is used to insulate inverted roofs, basements, car park decks, and heavy-duty commercial, industrial and cold store flooring. However to get BC off your back you can use a epoxy DPM and sand scatter it before it sets. C. 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). Dig the oversite ground to whatever height allows your hardcore, insulation, blinding, slab,screed. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. Norfolk. The correct installation of polythene DPM, rigid insulation and separating layers are highly important to the. Alan Jackson - Commercial Manager UK and Ireland - Gypsol. 1 Feb 2010. The DPM can be used as either below the slab application, directly below the flooring surface or in a sandwich construction, between base concrete and the screed. Registered Office: 6 Acre Close, Rustington, West Sussex BN16 3PG. Made from a combination of sand, cement and water, usually in a sand/cement mix ratio of anywhere between 3:1 and 5:1. 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. CSC screeding was very efficient that they screeded our floor in under 4 hours (around 91sqm) with the help of the Mixamate. 9. dthobhani; 18 Mar 2011; Floors, Stairs and Lofts; Replies 2 Views 1K. •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. What do think? What if we're pouring one of these strong self. The DPM (Damp Proof Membrane) is laid under the insulation on top of a soft blinding to ensure it is not punctured. The outcoming drain will have the dpm taped to it all the way around. 6 March 2017 at 8:04PM edited 6 March 2017 at 8:59PM. Sealing a patch of DPM around its edge to the old is easy, just use silicone goo. If the applied DPM is still very tacky, this1. That seems to be the recommended practice but I'm not sure how many bother with the one on top. Yes it is a small breach on regs but would be up to building control to decide. Buy Now. 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. If the DPM is still wet you should have not tiled over. Country. #2. You must design out the (damp/thermal) vulnerabilities associated with raft type foundations as they can be a headache. The screed will be only ~50 max (not yet dug any up). It’s primarily designed for brushing onto concrete floors and fine concrete screeds. #2. The guy doing it tried to compensate by using more adhesive and most of the wood has. 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. floating construction then a second "slip". Our highly experienced team of technical experts are here to offer help and advice every step of the way! Dependable Deliveries. These can over time allow a build up. This is usually a simple 1200 gague polythene membrane and sometimes a more complex drainage membrane or liquid DPM. FlexiDry said: Yes laying the screed direct onto insulation is standard practise for a floating floor. 100mm c35 concrete with mesh. Sunny Hampshire. If you are just trying to take a hollow out get a long straight edge and use a marker pen to mark out the perimeter of the hollow. 2: Fill the gaps with concrete, lay a DPM over it, insulation, then a concrete / fibre screed. Can be used under a surface DPM Excellent flow characteristics Protein-free and low odour USES Bostik Screedmaster Flow is a two-part, protein and casein free, cementitious underlayment with improved flow for smoothing uneven floors prior to. 1200 Gauge DPMs should be used when a floor is direct to the ground. 1. Insulation is laid on the concrete and covered with a screed. Brian shows how to correctly fit a Damp Proof Membrain - DPM in a new build houseLink to the T-Rex tape Website Http://bodgeitwithbri. The liquid membrane forms a strong seal and makes a permeable layer to enable moisture to evaporate off. . Produced from Recycled Material. • Unbonded (i. Hi I have fibreboard underlay in the instructions for the underlay it states if using this product on ground floor you should also use vapour barrier or damp proof membrane beneath the underlay. 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. ← Installation of rigid floor insulation on ground floor concrete substrates to receive screed. Trusted Trader, said safety must be a priority after a flood. Bostik Screedmaster Rapid DPM is a ready for use; one part, water-based damp proof membrane. If there is an operational DPM beneath the concrete you don't need one on top. In addition to the damp proof membrane (normally a 1200-gauge polythene sheet below the insulation), a 500-gauge polythene VCL.