. Once set, you can then apply your screed flooring to the DPM base. It is essential that this. The bitumen is about 20 mm thick and, I believe, serves as moisture barrier as well as an 'appearance' finish. Made from a combination of sand, cement and water, usually in a sand/cement mix ratio of anywhere between 3:1 and 5:1. The advantage of having the foundation. 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. Beam and block floors may need a levelling screed or grouting to ensure base level. As a waterproofer, BAL DPM is an easy two-coat system when used with BAL Self-Adhesives Butyl Tape in corners and junctions. 100mm **concrete base*. My house has a solid screed floor throughout the downstairs, with a Damp proof membrane about 100mm down. Prime and reapply , then screed to level and tile. This reduces the risk of harmful interstitial condensation by ensuring that any moisture within the. 14) Screed. Apply ARDEX DPM 1 C to protect the floorcovering installation from residual construction moisture and ground bearing moisture. 21. The difficulty is getting the underneath concrete to have a flat surface at exactly the right level. Material. The advice of a structural engineer should be sought for any exceptional point loads in the design of the floor. It should be waterproof to prevent any rising damp getting through. Because we were laying Karndean Flooring to a new extension we needed to check the % RH(relative humidity) of the concrete with a hygrometer. Like x 2; Agree x 2; List (You. 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. Fibreglass 1. Discussion in ' Builders' Talk ' started by barnjules, Jan 30, 2017 . Packaging: 25kg bags. Where screed is laid on top of insulation, screed should have a minimum depth of 65mm. Used the primer neat as guidelines suggested. AFAIK - PIR insulation boards need have a DPM under them to protect the board. 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. Insulation will then go on top and the screed layer would go over the whole lot. Refer to manufacturer’s guidelines. Will prim t be okay as primer on top of turbo? Thanks Pete Unless designed otherwise, the minimum specification for all partitions should be: sill and head plates 63mm x 38mm. carpet, tiles etc. 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. Get it level then when it is dry and can screw through floor board into blocks. I recently had a new boiler installed and new radiators fitted, and the plumber has cut the old copper. Your privacy. The builder wants to apply a DPM to the top of the slab before it is dry. 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. Do you need DPM under garage floor? Solid floor The existing concrete floor can be used as a base, however a new damp proof membrane (DPM). ; Stiffness: Concrete floors generally possesses adequate prudery & does not parry under the applied load which result in generating problems in non-structural elements, e. Don't think it will make much difference tbh, if you go the timber route use 22mm plywood instead of chipboard though. 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. . Roger Kenworthy on 2021-08-13 17:59:40: Question:Durability: A befittingly developed floor screed will outlast the else modules of the building. 8mm2 at 6mm 1. It’s only to stop the screed running under the insulation. We could scrape up the tiles and start again. Depends where the UFH pipes are. I was then able to put in a dpm and a hefty layer of cellotex and then screed to the level of the house. 1200g dpm. Cement screed is the most commonly installed type of screed and is suitable for both interior and exterior surfaces. Brian shows how to correctly fit a Damp Proof Membrain - DPM in a new build houseLink to the T-Rex tape Website Http://bodgeitwithbri. 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. But this all begs the question of why the hallway is so wet. I could put the dpm under the concrete which would be as effective. You also mentioned that there are vinyl tiles over the floor. Hi All come across this forum and would really appreciate some assistance. It’s primarily designed for brushing onto concrete floors and fine concrete screeds. Information ARDEX DPM 1 C. But what I dont understand is what to do to. 2 of the internal walls in the older building will be left as bare stone,. If modified screed is used you can get down to 55mm. Sealing a patch of DPM around its edge to the old is easy, just use silicone goo. DPM’s must be carefully protected where folded up the perimeter walls, and lapped under the DPC particularly at door openings. It is much easier to work on sections of the floor than try to achieve an even finish across the whole floor in one go. Be very careful by rushing. Capital Valley Plastics Ltd Damp-Proof Membrane Black 1200ga 25m x 4m (47163) (55) compare. Most damp-proof floor coatings are applied directly to the concrete floor surface using a brush or roller. Spoke to makers of UFH system. Vac up any loose sand once it's set and then tile. Under Floor Heating; Screed Care; Testing; Tips; Blog; Contact; A Practical Guide to Screed Testing: What Do the Experts Say? Download. Damp Proof Membrane is intended for use within solid concrete floors to prevent the rise of moisture or damp through structure flooring. 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. someone suggested removing the blocks on the inside along the width of the bifold and screeding all the way to the brick course. I laid the conc slab badly about 6 years ago ( did the whole shed in one hit 75m2, but my workshop is athird of the shed, so 25m2 wants levelling). g. If you don't allow the screed to dry properly, the moisture will be trapped within the screed potentially causing failure. 6. 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. It's a complete lack of knowledge on your floorlayers part or possibly just a carpet fitter trying his luck. Size is 4m x 4m. • GG500 – 500kPa. Acknowledgement : The Concrete Society. We are in the process of having an extension built. Care must be taken to a) ensure there are no holes or tears in the sheet that could allow. blake floyds; 23 Jul 2009; Building; Replies 3 Views 5K. 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. In both cases the surface on which the dpm is laid needs to be as smooth as possible. 5-10mm thick. Yes. Your builder or yourself should have laid dpm under the dpc course on top of the hardcore Base laid on soft building sand . the cut. 12) Tiles glued. Our Liquid DPM can be used on walls under a render to create a flexible waterproof layer. The DPM should: have sealed laps of at least 300mm wide link with wall DPCs to form an impervious barrier to. pf flooring, Jul 28, 2015 #20. Floor under carpet marked with chalk for wet areas. . Ideally there should be suitable insulation below the underfloor heating pipe to resist the heat going downwards. In addition to the damp proof membrane (normally a 1200-gauge polythene sheet below the insulation), a 500-gauge polythene VCL. These black DPMs can also be used with underfloor heating - under normal operating conditions this will not adversely affect the membrane. bandejapaisa; 30 Jun 2023; Building; Replies 5 Views 1K. concrete slab. TB243. We've just had our garage converted and our builders have laid a screed floor. 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. Unless there is an easy way. from a purely technical point of view a screed should always be divorced from the substrate by means of an operational DPM. DPM's must be carefully protected where folded up the perimeter walls, and lapped under the DPC particularly at door openings. Pumped anhydrite floor screeds are not much dearer than ready-mix sand/cement, costing around £25/m3 (laid to a 50mm depth). Spoke to makers of UFH system. Alan Jackson - Commercial Manager UK and Ireland - Gypsol. Like a lot of houses of that age, the ground floor is bitumen/asphalt over a concrete screed. ) • Floating (used to enable installation of thermal or impact sound insulation). Do you need DPM under screed? What DPM is Required? If the hygrometer reading comes back above 75% relative. flooringman Well-Known Member. We have our own in-house delivery fleet of FORS Gold vehicles with Moffett mechanical off-loads delivering nationwide. 75m2 at 3mm, 1. apparently some of the screeds had a cold or hot bitumen in or under them. LAY DAMP PROOF MEMBRANE. Information ARDEX DPM 1 C. Currently, the central heating pipes and mains water pipes are all buried below the damp proof membrane, under the screed. If the applied DPM is still very tacky, this1. 300 dries very hard Bitumen is soft so not compatible. . weberfloor DPM can be applied on to concrete or cement based screed surfaces with a. An important benefit of Jablite Thermal Floor Systems are the speed of installation. I will post up a pic of the failed LVT in a minute for you! Screed seems to be getting damper. 4 Screed. Two coats will provide protection up to a maximum hygrometer reading of 95% RH. It needs: 100mm or more of well compacted type 1 MOT, sufficient sand to blind, DPM, insulation, screed. We are one of the leading manufacturers of advanced barrier technologies and design-based solutions for specifiers, contractors and builders merchants throughout the UK and Europe, you can count on Visqueen for product quality. 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. Fast drying screed cost. enquiries@visqueen. 250mu (1000G) Black Polythene Damp Proof Membrane (DPM) 4m x 25m (100m2/Roll) URN: 5004075. I'm not saying this is the best thing to use. screed over insulation. screed thickness. This allows for the full 5kg or just half to be mixed at once depending on the area to be covered. For unbonded and floating screeds, a DPM may be specified between the base slab and the screed. Curing under polythene 12 hrs 12 hrs Drying time to receive finishes - from removal of curing polythene sheet 50mm thickness and 50% RH. Diagram B39 - Proper sealing. Bonded Screed Maximum Depth. The dpm is still continuous but laid down in the trough to maintain damp proofing. A poorly compacted, damaged or weak screed should be completely removed by mechanical means and reinstalled correctly. If you noticed the buildup wording is different to the detail drawing, it clearly shows dpm on top of concrete. I'm thinking dpm under the floor board and then 3:1 motar under the DPM to bed on the blocks. Jabfloor 70 has a nominal 1% compression value of 21kPa (2. I see some under the wood bearers, so hopefully this will keep the base dry. 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. 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. Kitchen floor, underfloor heating, screed and DPM. Staffordshire. In terms of where the insulation should be placed, it can either be placed under the slab or between the. I would use 100mm x10mm frame fixings, especially in screed because it is weak. Temporary protectionI had part of a 9" wall knocked down for a doorway. The OPTIM-R VIPs should then be fitted from the corner following the installation instructions. The bitumen adhesive also contained the same asbestos fibres. If the property is 200 years old it won't have a DPM under the concrete slab so its sitting direct on. Sand / Cement screeds must have a moisture reading of less than 75% RH before work. Try it free. #1. 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. The water got under the DPM and wet the slab and blinding layer. Ideally with a screed pump. This will give calculated u-value of 0. Our team of highly experienced technical experts are always on hand to provide the highest level of support and advice to our customers. Kingspan GreenGuard is available in a range of compressive strengths starting at 300 kPa 10% compression. My DPM was these tiles that were bitumnned/black jacked to the floor. 4. This told us tha. If under the screed this is normally a polythene dpm so the screed is then an unbonded screed, whereas if the dpm is on top of the screed an epoxy-type dpm is used. Can you put DPM over screed? Liquid DPM is a system that is used over a base floor. Stack Exchange Network. 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. Mark El-Kadhi New Member. Also, even with 80mm screed directly over Celotex the sab can feel a bit "hollow". 0. The Concrete slab will have been placed in January so it's had about 8 months to dry out. Renovation of more than 25 per cent of a solid or suspended floor involving the replacement of screed or a timber floor deck would have to meet the standards required by the building regulations Approved Documents. 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. 22 August 2019 at 10:27AM. Aug 18, 2010. All tiles and sand cement screed removed and last remaining suspect area. framing joints secured with not less than 2 nails per joint. But too much water will extend the drying time and. Contact Us. if there is insulation also under the screed i. A laminate wll be glued onto that. He intended to stick the floor to the bitumen DPM. "Remove water with pumps or buckets and contact your insurance company straight away. However to get BC off your back you can use a epoxy DPM and sand scatter it before it sets. 3. You are therefore at the edge of the joists capability. 21m2 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. Reaction score. The plan was to lay American Black Walnut but the hallway floor was not level. To remove this type of asbestos containing floor. 2m3). moisture can still transfer through the screed albeit at a slower rate. 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. For a self-levelling screed a system such as Flowcrete UK’s Hydraseal would be used. 40mm traditional sand and cement screed. then ducting should be provided to allow air through the solid floor and into the void under the existing house. Below Floor Screed 1. Lay and level the concrete slab, allowing sufficient time to dry out, as per BS 8203. Ltd. Seems fine so far. 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. 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. Walkable in 6 hours. This allows for the full 5kg or just half to be mixed at once depending on the area to be covered. 1. Discussion in ' Builders' Talk ' started by Liz990, Feb 21, 2021 . Complies with BS 8485:2015 + A1:2019 - industry standard for methane and carbon dioxide protection. Mapeproof One Coat is not recommended for heated subfloors where wood floor coverings are to be installed. For guidance on using DPM One Coat Membrane with screed products refer to the individual ScreedPro Data sheet concerned. ARDEX DPM 1 C may be used if; 1. Then mix up the high performance stuff as that is fibred and can be taken to a feather edge. above the slab I am having a screed to cover the UFH pipes. Then use the correct screed. 6 March 2017 at 8:04PM edited 6 March 2017 at 8:59PM. 17 May 2010. Trusted Trader, said safety must be a priority after a flood. 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. Types of Liquid DPM. New-build install: £50 to £75 per square metre. 1 left. The reasoning behind the 'sub-base:bedding' school of thought is that the membrane prevents the bedding from trickling down or being washed into any voids within the sub-base material, while the 'sub-grade:sub-base' orthodoxy, in which I include myself, maintains that keeping the sub-base material from mixing with the sub-grade, and reducing or. Our quarry tiles were pretty much laid on dirt so there were some big variations in height over the whole kitchen. Screed. 67. I don't understand how to bridge the cavity under the bifold without filling the cavity or compromising on structural strength. 13) Polypropylene. pipes or cables for under floor heating should always be installed on top of the tanking membrane, not beneath it. Mine is below the concrete. 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. 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. Slightly below floor level are two layers of polythene membrane with a layer of floor levelling screed to make up to floor level. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. 90 per pack | Buy now from UK Flooring Direct. Ideal for use in shower areas where screeds are laid to falls incorporating a damp proof membrane. Insulation is a crucial consideration for UFH. There are many proprietary screeds on the market and information about these can be obtained from the manufacturer. 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. #3. At its deepest it’s 150mm, what I’m stuck with is the builders trying to push on with the job. The main drawback. rev 2023. The dpm is extended and taped around this opening. It is also recommended that light reinforcement be used. Pricing. The membrane is manufactured in standard 125mu, 250mu, and 300mu thickness and in roll sizes of 1. Misinformed on this as he had put a dpm under the chipboard. Tape is a non starter. The company keeps abreast of market developments by. It is advisable to incorporate a light mesh within the raft for reinforcement. with the concrete but the insulation. Complete range, complete solution. That seems to be the recommended practice but I'm not sure how many bother with the one on top. In terms of where the insulation should be placed, it can either be placed under the slab or between the slab and the floor screed. This self leveling concrete’s use of latex. Diagram B38 - DPM lapping under DPC for thickness of inner leaf. Before screeding can commence the area to be screeded must be made watertight to prevent leakage. #5. Buy Now. This can only normally be guaranteed if its an new build or extension and most houses have been sold, inherited etc. 45sqm to supply and fit. Bring the membrane up the surrounding foundation walls until it is just high enough to connect with or form the wall damp proof course. This barrier is intended to stop moisture passing from one to the other. Property is mid 1960s, solid ground floor. There will be a DPM under the slab and up the edges already. There is a membrane underneath the concrete slab which has been poured and it comes up and meets the dpc. The subfloor. Unbonded Sand and Cement Screed Minimum Thicknesshelppppppppppppppppppppppppp just had to quote for screed flooring. . 2. 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. hot bitumen, or cold bitumen in solution. The dpm needs to be clean and dry. 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. 27 Dec 2020. 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. Alan Jackson - Commercial Manager UK and Ireland - Gypsol. Renovation property: £60 to £85 per square metre. steve have you checked the level of all of the concrete floor. 29 per m², £42. not bonded to the base – typically where a DPM is placed under the screed. Yes run the dpm up the wall to connect wall dpc with floor dpm. Non-structural floor screeds shall be adequate for the location and intended use, and provide a suitable background for floor finishes. When stripping the bathroom, the area under the bath tub was bare concrete, lower than the rest of the "black" floor throughout the property. Firstly, there was no need to use a liquid dpm if you used underlay with a built in vapour barrier. Insulation sheets should be laid tightly together with the joints staggered to avoid movement. Use 1000 gauge or thicker – ideal for this is the polyethylene use for the DPM under your concrete subfloor. The insulation should not be stepped as this can act as an anchor point and cause cracking in bridging or on the screed under movement and cause weak spots in a void underneath. Ok so I have drawn the attached image. How to Damp proof a floor and walls using synthaproof as a damp proof membrane is shown in this tutorial. A few months have passed since then and is now on average 2. Resin and cementitious floor finishes combining performance and design. Sunny Hampshire. Alan Jackson - Commercial Manager UK and Ireland - Gypsol. 5 ratio of cement to sharp sand. Let the slab dry first. This is done to maintain energy efficiency and prevent. Changed mate!constructed as a separate concrete (Figure 2) or concrete masonry (Figure 3) perimeter foundation wall with the slab laid later. royaloakcarpentry Senior Member. 8 Oct 2015 #4 So you have a concrete slab laid on a DPM, and later a 65mm sand & cement screed laid on the Extn. Ideal for use where there is no functioning structural DPM (common in older properties). The old adhesive should of been removed. The previous concrete floor failed due to a lack of DPM and has now been removed. #1. 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. Do your slab as intended, single course of brickwork around the perimeter, then build your frame. Some houses in early 70s don't have a DPM as I've found out over the years. DPMs on top of the slab, i. The dpm has added to the problem by removing any bonding capabilities within the floor screed. This generally takes 1-2 days, depending on the thickness of the floor screed. No this is designed to be used under floor screeds, tiles, render or plaster. First, divide the floor up. 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. 4,049. Posted July 28, 2021. 9. phatboy. He also saw hairline cracks in the top layer of screed in places. Once set, you can then apply your screed flooring to the DPM. 21) Timber block. I will be tiling over the screed so looking for the simplest option. Jan 24, 2019. ORDER LINE 0800 047 6775. But on the basis of more insulation is better, consider fitting more and laying cupboard flooring on top, or on joists. Hi guys. Im surprised the floors lasted that long 300 will fail over bitumen everytime. We need to raise one level by 6mm then screed then laying 2. Depending on the use of the building, the slab can then be finished ready for use, or receive a screed suitable for a floor finish. 3. . DPM, Celotex, 1000 gauge poly, 100-150mm concrete with or without reinforcement, 50-80mm screed. Warm water systems, such as those available at The Underfloor Heating Store, feature an array of pipes, laid just below the surface of your floor. £12 - £16 per m2. hours for Ceramics. 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. The total floor insulation cost will have two elements – the cost of materials and. studs 63mm x 38mm at maximum 600mm centres. With the number of planning applications for basement extensions rising by 183% according to research by Halifax, tilers need to be. 14 assuming 0. I was planning on putting 1200g DPM down, then 80mm celotex insulation (taped at joints), then 65mm screed (approx 1. 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. Then a primer like the one you have at 4-1 then if needed another coat at 2-1. However the tiler should apply a Primer before screeding such as StopGap P141. Issues to be taken into account include: installation. Notch7. screed finish over the insulation to match existing floor levels. 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. Just lap the whole room up as normal, blobs of. PermaSEAL Liquid DPM can also be applied to concrete floors below screeds. DPC and DPM are lapped together at this stage. This was due to a neighbour redirecting the water from his gutters. As to joining - take bricks down to the bottom of the insulation later and run your insulation (which I presume is celotex type) into the opening, screed over insulation level. DPM is normally used in floors. #3. Air bricks are. #2. £20 per m2. But others are direct to earth, brick, rubble what ever. i'n not farmiliar with wickes dpm and the primer used for professional (if you like) screeds is neoprene. Looking for best method to both level and damp proof the concrete, to then be covered with a thin layer of celotex, then engineered wood or laminate. 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. We have a few options: 1. Suitable for most construction damp proofing requirements. FlexiDry said: Yes laying the screed direct onto insulation is standard practise for a floating floor. 150mm PIR insulation. Used the primer neat as guidelines suggested. 3k. doors. .