2. Suitable for use with underfloor heating and for encapsulating electric cable undertile heating systems. 17) DPM under slab. 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. 30811761. For example, when installing Celotex under floor. ORDER LINE 0800 047 6775. Preparation is key with these coatings and the substrate must be sufficiently clean and dry. (DPM) with joints well lapped and folded. 100m² per roll. DPM sheets should be overlapped by at least 300mm. This barrier is intended to stop moisture passing from one to the other. The floor originally had a carpet laid on top of the tiles, when I lifted it nothing felt, looked or smelled damp. The extension is yanked and the architect has spec'd Marley Dampseal for the dpm which will sit under 60mm of Kingspan and 75 mm of screed. The ground floor is wooden floor boards and there are 2 rooms I need to do. com. Sunny Hampshire. DPM, Celotex, 1000 gauge poly, 100-150mm concrete with or without reinforcement, 50-80mm screed. So, as money's too tight to mention round here, I replaced the leaking door with a cheap UPVc one. 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. Customer asked me how did they stop rising damp before the Dpm sheet was used and it made me think ( that hurt ) . The bitumen adhesive also contained the same asbestos fibres. This barrier is intended to stop moisture passing from one to the other. An important benefit of Jablite Thermal Floor Systems are the speed of installation. Brian shows how to correctly fit a Damp Proof Membrain - DPM in a new build houseLink to the T-Rex tape Website Http://bodgeitwithbri. Liquid DPMs gave the best protection but were more expensive. if your DPM were above the concrete, the uFH would be heating a large damp lump of concrete. Curing Under Polythene 12 hrs 12 hrs Drying Time To Receive Finishes - from removal of curing polythene sheet 50mm thickness and 50% RH. 30 Jun 2023. Screeds are covered by BS 8204, Screeds, bases and in-situ floorings, (2004). T ·Öà 4 ·Öò 8 ·Ñ• 2, Jun 15, 2007. How to install vacuum insulation panels below a floor screed. 10 Feb 2020. "Document any damage for insurance purposes. 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. Would that require two layers of DPM? For example: Level layer of hardcore; Layer of sand blinding; DPM; Concrete slab at a thickness of 3" inches; DPM (?) Jablite 70 floor insulation (75/100mm thickness) Vapour control layer ; Screed (1. Insulation is laid on the concrete and covered with a screed. With a laser. The DPM should come up in an upstand and tie into the DPC on the. Location. 100mm c35 concrete with mesh. 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. Walkable in 6 hours. The vinyl that was laid bubbled up, so contractor removed it. My query is regarding the floor insulation, damp proofing and screed. They can therefore be laid under the DPM (the DPM is still necessary to prevent. 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. Once set, you can then apply your screed flooring to the DPM base. 29 per m², £42. ) chrysotile (white) asbestos fibres. Curing Under Polythene 12 h 12 h Isocrete K-Screed (Heavy Duty) COMPRESSIVE STRENGTH (28 DAYS) BS EN 13892-2 >30 N/mm2 BRE TEST CATEGORY BS 8204-1 Category A. Let the slab dry first. Give it a good wipe with a damp cloth and let it dry before you start. 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. I am assuming its asphalt with a bitumen top layer, 10-15mm thick. As a waterproofer, BAL DPM is an easy two-coat system when used with BAL Self-Adhesives Butyl Tape in corners and junctions. do I still need a DPM under that insulation? it is internal and sitting on a structural slab that is wrapped in DPM externally. 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. It stops around 10mm away from the internal walls in all rooms. For this, a metal mesh standing with plastic pillars ( (feet) will be laid before the concrete is. I was then able to put in a dpm and a hefty layer of cellotex and then screed to the level of the house. Insulation will then go on top and the screed layer would go over the whole lot. 3) 50mm - Screed with Concrete Fibres, on top of the insulation boards. DPMs on top of the slab, i. I really need to get the living room useable for my family and am hoping that a dpm under the engineered wood is possible. then ducting should be provided to allow air through the solid floor and into the void under the existing house. Firstly, there was no need to use a liquid dpm if you used underlay with a built in vapour barrier. DPC and DPM are lapped together at this stage. 500g Single Wound Polythene-2. This means of course I can't get a DPM under the slab; is it ok to put the DPM over the concrete slab, and then put down 50mm insulation and then 100mm screed? Ed209 , May 1, 2020 #1Assuming 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. These tiles have failed as some are missing/ some broken/ the bitumen broken down, meaning the DPM has failed, hence allowing the water through. Only one coat though. It is essential that this. Before screeding can commence the area to be screeded must be made watertight to prevent leakage. 0. 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. If DPM ok then. The bitumen is about 20 mm thick and, I believe, serves as moisture barrier as well as an 'appearance' finish. Looking for a FLAT membrane as I am told the creases you get when you unfold 4m wide DPM / polythene from a 1m roll can cause cracks (plus its a real pain to lay). 2) 25mm - Celotex TB3000 Insulation Board. 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. Its an easy job to do yourself - also check Seconds & Co for PIR. Do your slab as intended, single course of brickwork around the perimeter, then build your frame. 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. Fibreglass 1. Location. Applying Damp Proof Membranes. It is important to ensure that a proper seal is achieved around all services. UFH inside plastic polypanels 75mm screed (probably not liquid). There will be a DPM under the slab and up the edges already. 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. Try it free. Pre screeding, you lay the DPM, install the insulation sheets and create vertical upstands of insulation block around the outside perimeter of the wall. 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. This allows for the full 5kg or just half to be mixed at once depending on the area to be covered. #3. 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. not bonded to the base – typically where a DPM is placed under the screed. Polycote DPM Primer is a superb twin pack high-performance epoxy coating that. It is black/blue in colour and comes in conveniently multi-folded rolls. I recently had a new boiler installed and new radiators fitted, and the plumber has cut the old copper. Firstly, there was no need to use a liquid dpm if you used underlay with a built in vapour barrier. The liquid membrane forms a strong seal and makes a permeable layer to enable moisture to evaporate off. Reinforcing concrete. It's joining onto the garage I'm converting so the whole floor is getting built up with polythene DPM,. . Im surprised the floors lasted that long 300 will fail over bitumen everytime. This reduces the risk of harmful interstitial condensation by ensuring that any moisture within the. is that do-able? if so, can I just run the DPM 1 course above DPC? it's too late to tuck. Damp proof membranes (DPMs) can be used to help resolve damp issues which already exist or to avoid damp or moisture problems in. 1 tonnes per m²), which is suitable under a 75mm screed in normal domestic situations. Like a lot of houses of that age, the ground floor is bitumen/asphalt over a concrete screed. Renovation property: £135 to £185 per square metre. i'n not farmiliar with wickes dpm and the primer used for professional (if you like) screeds is neoprene. . Unless there is an easy way. do I still need a DPM under that insulation? it is internal and sitting on a structural slab that is wrapped in DPM externally. 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. 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. For reference, screed is a thin layer of concrete poured over a floor base. f) whether there is an effective dpm within or under the existing base; g) whether the screed is to provide the wearing surface, if so, the type and intensity of traffic to be expected; h) if not a wearing surface, the type and thickness of the finished flooring to be applied; i) type of underfloor heating (if any) to be used; applications are suitable for bonded topping screeds. Right based on those joist spacings and dimensions the joists should easily accept 1. Our self levelling compound, or floor screed, is available in a wide range of varieties for a multitude of floor installation applications. This can include timber floors, tiles, laminate flooring and carpet. FlexiDry said: Yes laying the screed direct onto insulation is standard practise for a floating floor. I will post up a pic of the failed LVT in a minute for you! Screed seems to be getting damper. 5kg multi chamber bags. TB243. g. Liquid DPMs gave the best protection but were more expensive. Insulate under the floor using the crawl space underneath. Reinforcement is required when you’re concreting areas that will be subjected to heavy loads, such as garages and car parks. 1314. The minimum sand and cement screed thickness would be 40mm as defined by the British standard. 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. of the screed should be checked by the Main Contractor. Reaction score. Screed & Insulation. 75m2 at 3mm, 1. the cut. sandwiched under the screed, were also common and usually in liquid form, e. Energy Efficiency: Concrete floors generally possesses lofty thermal mass & this may be. 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. As a rough guide, laying a conventional sand/cement screed costs around £15/m2, increasing by around £5/m2 when delivered ready-mixed. moisture can still transfer through the screed albeit at a slower rate. Country. Also there is no DPM under the slab. Renovation property: £60 to £85 per square metre. As with the Kooltherm installation, start by ensuring a clean and level surface. Installation systems for tiling and natural stone. 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. For technical support please call. 00 per roll. The option of 50mm insulation between battens is appealing. 1200g DPM will be fine. 2. SikaBond® Rapid DPM is a single part moisture curing polyurethane. The specific liquid DPM system will depend on the type of substrate or screed. Learn More Damp Proofing 15 Items DPM Handy Pack - 300mu 1200 gauge - 4m x 5m Rating: 2 £17. Mapeproof One Coat is not recommended for heated subfloors where wood floor coverings are to be installed. Hi All come across this forum and would really appreciate some assistance. All other sheet membranes can be used with unbonded toppings. For a self-levelling screed a system such as Flowcrete UK’s Hydraseal would be used. Visqueen EcoMembrane DPM. 00. 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. Country. screed finish over the insulation to match existing floor levels. Thanks for reading. Visqueen 2000 gauge Polythene - 12. This will allow the screed to. View complete answer on allthingsflooring. It may well require the re cement to be removed, a liquid dmp used with dry sharp sand thrown on it before it dries, and then use a flexible self levelling screed. However to get BC off your back you can use a epoxy DPM and sand scatter it before it sets. Posted July 28, 2021. Fintan has been involved extensively in a deep energy retrofit of a property to the Enerphit standard in the west. An expansion gap may be necessary around the edge of the floor finish in screed or. pipes or cables for under floor heating should always be installed on top of the tanking membrane, not beneath it. Complies with BS 8485:2015 + A1:2019 - industry standard for methane and carbon dioxide protection. 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. Labour costs. £12 - £16 per m2. The idea is that you are to prevent any screed material from falling down any joints and coming into contact with the cold slab. Applying Damp Proof Membranes. Aug 18, 2010. The previous concrete floor failed due to a lack of DPM and has now been removed. C. "Remove water with pumps or buckets and contact your insurance company straight away. Use polyethylene sheeting to create a waterproof membrane to ensure that there is no leakage of the screed when it is pumped in wet. If in the screed then no problem with this. uk ;. Jan 24, 2019. It should be waterproof to prevent any rising damp getting through. I will be tiling over the screed so looking for the simplest option. 100mm **concrete base*. #2. The surface should be of sufficient quality and. In any case, it’s best to use a specialist to avoid damaging the floorboards themselves. The floor is concrete slab, 100mm Kingspan PIR, DPM and then 70mm screed. Let’s hope you have a good water table as that’s the wrong dpm used. Ideal for use in shower areas where screeds are laid to falls incorporating a damp proof membrane. New-build install: £50 to £75 per square metre. 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. 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. take account of possible differential movement. Traditional screeds. #5. 5m) It will have 50mm insulation boards on top of it, followed by 18mm/22mm. A suitable gauge damp proof membrane (DPM) and thermal insulation must be provided. 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. Apply ARDEX DPM 1 C to protect the floorcovering installation from residual construction moisture and ground bearing moisture. blocking/nogging for support of plasterboard 43mm x 38mm. Use polyethylene sheeting to create a waterproof membrane to ensure that there is no leakage of the screed when it is pumped in wet. Should I lap DPM under or over Dpc then celotex, then another DPM lapped up the wall with 25mm up stands. 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. Hull. Buy Now. #2. concrete slab. Then use the correct screed. New-build install: £50 to £75 per square metre. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. . 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. 14) Screed. At the moment, there is a dpm under the patio door overlapping the cavity and meeting the main dpc which comes up from the slab and wraps around the inner bricks. At its deepest it’s 150mm, what I’m stuck with is the builders trying to push on with the job. 3 Oct 2004. Apply sand-blind base (this base should be level to within 5mm along any 3m straight edge). You will need to tear the lot up. Said he'd provide a quote but didn't come back to me. Cushion Ultra Silver Wood 10m² Underlay: The best laminate underlay for damp protection. Our highly experienced team of technical experts are here to offer help and advice every step of the way! Dependable Deliveries. 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. There will be a damp-proof membrane under the insulation and possibly a second membrane on top, depending on the type of screed. Floor under carpet marked with chalk for wet areas. 1: Fill the gaps with concrete and get an asphalt company to lay an asphalt screed over it to restore the DPM. Laying new floor - needs DPM? dunroving Posts: 1,881 Forumite. 1. A latex based screed isnt as affected by moisture/damp as a water based is. #1. 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). 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. The dpm needs to be clean and dry. This barrier is intended to stop moisture passing from one to the other. The membrane is manufactured in standard 125mu, 250mu, and 300mu thickness and in roll sizes of 1. Refer to manufacturer’s guidelines. The difficulty is getting the underneath concrete to have a flat surface at exactly the right level. 5mm = 2. DPM is usually below the concrete, then the insulation, then a polythene sheet to stop the insulation floating as the screed is poured. Spoke to makers of UFH system. 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. DPM (1200 gauge visqueen) Old Concrete Slab. 65mm Screed. Celotex PIR’s closed-cell, moisture-resistant composition helps to prevent water ingress. Used the primer neat as guidelines suggested. In the attached photo I have removed poorly laid DPM and insulation boards with a view to starting again. g. Hello, I have noticed some funny things going on under the floor of our recently bought house, which was originally built in 1905. #2. 12) Tiles glued. What the DPM is attached to can fail. studs 63mm x 38mm at maximum 600mm centres. UFH Pipwork. All modern buildings have what is known as a Damp Proof Course. These can over time allow a build up. Kitchen floor, underfloor heating, screed and DPM. 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. Use 1000 gauge or thicker – ideal for this is the polyethylene use for the DPM under your concrete subfloor. Ltd. The total floor insulation cost will have two elements – the cost of materials and. 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. There are great benefits to be had by utilising calcium sulphate screeds, mainly due to their ability to be pumped, therefore reducing the time that screeders need to be on site. 4. What is liquid DPM? Liquid DPM is a system that is used. 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. . Two coats will provide protection up to a maximum hygrometer reading of 95% RH. 22 August 2019 at 10:27AM. DPM under block and beam. How to Damp proof a floor and walls using synthaproof as a damp proof membrane is shown in this tutorial. Information ARDEX DPM 1 C. 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. 28. Thin screed to level old concrete floor. If Under floor heating is used It is essential that the pipes are laid on. Prime and reapply , then screed to level and tile. But others are direct to earth, brick, rubble what ever. Depends where the UFH pipes are. Insulation Below A Floor Screed. 100 hardcore, 50mm builder's sand to blind, 1200 gauge DPM, 70mm insulation (Celotex, Kingspan, etc. B. blake floyds; 23 Jul 2009; Building; Replies 3 Views 5K. Bring the membrane up the surrounding foundation walls until it is just high enough to connect with or form the wall damp proof course. The builder wants to apply a DPM to the top of the slab before it is dry. 5sqm has blown. 2m3). However the chance that the floor tiles or adhesive can release fibres and become respirable when disturbed is very low. Insulation is a crucial consideration for UFH. 3. If the coating is not going to be the final decorative surface and. com. This is resorted to only under the duress of severe time constraint. 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. If you are using a final floor finish which will be fixed to the screed’s surface using an adhesive then you will need to lightly sand the laitance off the surface of the screed before using a compatible primer and adhesive. 19)Cement. The dpm is extended and taped around this opening. It is not. Guidance on how to install insulation between a floor screed with Kingspan Kooltherm K103 Floorboard. you might just have a low spot along the old wall where the concrete meets the wooden floor. com Do I need a DPM under laminate flooring? Simply put yes. If DPM ok then. If in the screed then no problem with this. Could us a liquid dpm like Drybase (2 coats), then a sand/cement screed,with fibre reinforcment, 25mm is the minimum thickness for bonded screed, that's thin,might still crack, no need for primer with Drybase. An ARDEX Damp Proof Membrane will protect the floorcovering. 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. Mark El-Kadhi New Member. I think underfloor heating would work if you layed DPM, insulation (as much as poss) woodchip flooring and don't use a screed. 5. Had a look at the pics and IMO no dpm under the subfloor. The position would vary in accordance with proposed methods of construction. CSC screeding was very efficient that they screeded our floor in under 4 hours (around 91sqm) with the help of the Mixamate. Choosing the solid concrete ground floor insulation is important for any project. Under Floor Heating; Screed Care; Testing; Tips; Blog; Contact; A Practical Guide to Screed Testing: What Do the Experts Say? Download. 5m2 at 1mm thickness 1. Then prime the marked out area. 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. Generally fairly high grade stuff too. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. It may be applied onto either a solid in-situ concrete ground floor slab or onto a precast concrete floor unit. To avoid such issues, it is therefore extremely important to make sure that the screeds are given sufficient time for drying. #1. You should use them to protect all final floor finishes. This will allow the screed to bond to the dpm. The polyethene slip membrane installed over the insulation must be overlapped and sealed to prevent loss of screed. hot bitumen, or cold bitumen in solution. Air bricks are. • GG300 – 300kPa. The same larger hole after I cut back some of the sandy concrete. Sealing a patch of DPM around its edge to the old is easy, just use silicone goo. #1. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. A traditional sand and cement screed is normally a 1:4 or a 1:3. The mat will get glued down to the screeded UFH, and then the. It is good practice to either fit another DPM or tape the insulation joints, when adding a screed on top of inso'. The screws or staples used to hold the pipePoorly installed sand/cement or calcium sulphate screeds can result in a weak or friable surface which is unsuitable for the application of subsequent subfloor preparation products and installation of decorative floorcoverings. We've just had our garage converted and our builders have laid a screed floor. 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. Stack Exchange Network. 25 Apr 2010. The old floor tiles do contain a small amount of asbestos ( Marley tiles etc. Once set, you can then apply your screed flooring to the DPM base. 8 Apr 2013. phatboy. However to get BC off your back you can use a epoxy DPM and sand scatter it before it sets. Im not quite sure where my DPC should be going. 4. The outcoming drain will have the dpm taped to it all the way around. Unbonded Sand and Cement Screed Minimum Thicknesshelppppppppppppppppppppppppp just had to quote for screed flooring. Manchester • Member since 5 Jun 2015 • 64 jobs, 95% positive feedback. 9. Care must be taken to a) ensure there are no holes or tears in the sheet that could allow. Option 1 is clearly cheaper but as long as it takes a screed floor (says it does) and gets signed off by. 6 March 2017 at 8:04PM edited 6 March 2017 at 8:59PM. 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. No need for double DPM. For traditional screed, the usual total will fall within the range £18. The Epoxy DPM 5kg is supplied in two 2. 74 inc. If modified screed is used you can get down to 55mm. 14 m-1 P/A and use of edging insulation. • GG500 – 500kPa. 99 Inc Vat. 4 Screed. 50mm C&S (1:4) screed towelled smooth. Effectively, a damp proof membrane (DPM) is used to create a barrier between a concrete (or screed) subfloor and a wood floor. The company keeps abreast of market developments by.