carpet, tiles etc. 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 told us tha. It stops around 10mm away from the internal walls in all rooms. Resin and cementitious floor finishes combining performance and design. Last autumn we knocked down an old conservatory and kitchen extension and built a new extension in the same place. An ARDEX Damp Proof Membrane will protect the floorcovering. Other benefits. Temporary protection should. This DPM is a ‘thick’ plastic sheet mostly 1000 – 1200 gauge polythene material. • GG300 – 300kPa. com. I would say the screed was. 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). 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. Currently, the central heating pipes and mains water pipes are all buried below the damp proof membrane, under the screed. I could put the dpm under the concrete which would be as effective. Fintan has been involved extensively in a deep energy retrofit of a property to the Enerphit standard in the west. Small hole dug through 2" soft sandy concrete to reveal hardcore and soil. The DPM should come up in an upstand and tie into the DPC on the. 67. #2. You now have a 'swimming. For a self-levelling screed a system such as Flowcrete UK’s Hydraseal would be used. 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 've dug down and put 100mm of concrete down will liquid dpm to meet up with the existing dpm and 50mm screed ontop easy. 500g Single Wound Polythene-2. screed (with UFH) 75mm. Overlap it and tape it with duct tape or 100mm pvc tape. Visqueen EcoMembrane DPM. The DPM we use does not cancel all moisture out as this will end up. Sunny Hampshire. 5kg multi chamber bags. DPM Membranes for Concrete Floors A range of high quality DPM membranes from Capital Valley Plastics, designed for use with solid concrete slabs. Made from recycled materials. For the best results, we recommend leaving it to cure for 28 days. Laybond Screedmaster One Coat Liquid DPM 2 part solvent free epoxy surface damp proof membrane developed to. Lay and level the concrete slab, allowing sufficient time to dry out, as per BS 8203. 001 Ardex Australia 2015 Bulding regs would require 100mm insulation and 70mm reinforced screed for this. However, when I hammer-fix the battens to the concrete I'm going to punch holes in my DPM. blocking/nogging for support of plasterboard 43mm x 38mm. If I did my external one at the same height then the outside floor height would sit very low so presumably I can put the external one at the same level as. 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. 65mm Screed. 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. On a job that’s had anhydrite screed pumped in, using a Wolff gm200 moisture meter readings in parts are 99. M. Can you put DPM over screed? Liquid DPM is a system that is used over a base floor. Reinforcement is required when you’re concreting areas that will be subjected to heavy loads, such as garages and car parks. The rest of the floor will be as follows (top down); flooring. For unbonded and floating screeds, a DPM may be specified between the base slab and the screed. I want to level my workshop floor. If you don't allow the screed to dry properly, the moisture will be trapped within the screed potentially causing failure. Choosing the solid concrete ground floor insulation is important for any project. With the number of planning applications for basement extensions rising by 183% according to research by Halifax, tilers need to be. I was hoping to use a recycled content DPM. As you are always relying on the subfloor surface strength you are always at risk if there is no sheet DPM under the floor as it will be under pressure. 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. 001 Ardex Australia 201550mm insulation would be better than nothing be it under screed or timber. The subfloor. Solid floor insulation –screed finish: Per m 2: £70: £90: £80: Labour: Per day: £180: £250: £215:. Hi, I'm doing a kitchen modernisation in my ex-Council house which was built in 1947. Damp proof membranes (DPMs) can be used to help resolve damp issues which already exist or to avoid damp or moisture problems in. The idea is that you are to prevent any screed material from falling down any joints and coming into contact with the cold slab. Ball and Co. Needs a dpm under it and i normally put one on top too - stops you accidentally sticking the boards to the insulation. Hull. All modern buildings have what is known as a Damp Proof Course. Drybase Liquid-Applied DPM should be used in situations where the final surface is going to be covered. It is advisable to incorporate a light mesh within the raft for reinforcement. Use polyethylene sheeting to create a waterproof membrane to ensure that there is no leakage of the screed when it is pumped in wet. How to install vacuum insulation panels below a floor screed. This will allow the screed to. As a rule self levelling screeds need an active DPM at some point below them other wise they will likely de-bond due to damp and this could be the reason it seems to be lifting easily. 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. It also looks like there could be polystyrene under the screed, this will be a barrier to damp coming from the ground. Whilst looking at the overall prices of each piece of work there's a couple of questions that have come up. £51. Traditional screeds. will come down and meet the insulation under the screed so the screed is totally floating. Option 1 is clearly cheaper but as long as it takes a screed floor (says it does) and gets signed off by. 14 m-1 P/A and use of edging insulation. Give it a good wipe with a damp cloth and let it dry before you start. 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. If DPM ok then. Applying Damp Proof Membranes. 50 /sqm. The polyethene slip membrane installed over the insulation must be overlapped and sealed to prevent loss of screed. •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. 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. There are two main options: 1. i'm you have gathered by now, you havn't left enough depth to do this. It should accommodate 0mm to 5mm (or thereabouts) It will cover an area of 26m2 (4m x 6. Im surprised the floors lasted that long 300 will fail over bitumen everytime. 3. In addition to the damp proof membrane (normally a 1200-gauge polythene sheet below the insulation), a 500-gauge polythene VCL. So I have a concrete floor in the kitchen (concrete - DPM - 50mm screed), knocked through into the outside toilet which just had soil floor. sandwiched under the screed, were also common and usually in liquid form, e. 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. I don't understand how to bridge the cavity under the bifold without filling the cavity or compromising on structural strength. 1. 12) Tiles glued. The bitumen is about 20 mm thick and, I believe, serves as moisture barrier as well as an 'appearance' finish. The position would vary in accordance with proposed methods of construction. 5m) It will have 50mm insulation boards on top of it, followed by 18mm/22mm. ARDEX DPM 1 C may be used if; 1. £20 per m2. Anhydrite (liquid calcium sulphate) screeds offer a number of advantages: They’re not much dearer than ready-mix sand/cement, costing around £25/m3 (laid to a 50mm depth). They can be used under resin screed finishes and are applied in thinner sections than standard cement screeds. first of all check your existing floor is perfectly level, if not then forget the freeflowing screed as it will not level up with the existing floor. xednim, Apr 6, 2019. 3k. AFAIK - PIR insulation boards need have a DPM under them to protect the board. The specific liquid DPM system will depend on the type of substrate or screed. 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. #2. 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. #2. The Epoxy DPM 5kg is supplied in two 2. . 5kg multi chamber bags. 4 so you have around 1. 1 or just a bit less. 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. 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. Visqueen ECO Membrane Data Sheet. It is not. Insulation is a crucial consideration for UFH. Can be used over underfloor heating. If you are installing where existing floors have been removed, check that there are no traces of previous adhesive residue. 3. 00. 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. Insulation Below A Floor Screed. The floor make up is compaced hard core, 125mm concrete, dpm, 100mm insulation, 75mm concrete screed ( polished and heated). Onto the concrete. 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. You also should have removed the vinyl tiles before priming and screeding. 1200g dpm. What you don't want to do, with a DPM under the screed, is create a moisture trap - which a second DPM would do. For traditional screed, the usual total will fall within the range £18. The DPM (Damp Proof Membrane) is laid under the insulation on top of a soft blinding to ensure it is not punctured. 5mm = 2. Let the slab dry first. Then use the correct screed. Ideally I don't want to screed the floor inside now as it will primarily be a workshop so I'm trying to retain as much of the 2. All waxes or sealers must be removed, and patching/leveling or embossing must be brought to a flatness of 3/16” in 10’. or as a sandwich membrane in base concrete or between the base concrete and screed. Ideal for use in shower areas where screeds are laid to falls incorporating a damp proof membrane. Our costs are ballpark averages – get a local tradesperson to quote now. JB Flooring Well-Known Member. I'm thinking dpm under the floor board and then 3:1 motar under the DPM to bed on the blocks. A latex based screed isnt as affected by moisture/damp as a water based is. Be very careful by rushing. Liquid DPM for Walls. DAMP PROOF MEMBRANE. Then the lamiante has trapped this water in creating the sweat. Learn More Damp Proofing 15 Items DPM Handy Pack - 300mu 1200 gauge - 4m x 5m Rating: 2 £17. 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. . Acknowledgement : The Concrete Society. In the attached photo I have removed poorly laid DPM and insulation boards with a view to starting again. The vinyl that was laid bubbled up, so contractor removed it. Mark El-Kadhi New Member. Relative Humidity: The moisture content or relative humidity of the atmosphere plays is a major factor that affects the drying time of the screed. • GG500 – 500kPa. Mobile Sales: 07920 715745. The work falls under building regs part L and you need minimum 70mm PIR insulation. 14 assuming 0. When incorporating under floor heating: Screeds should be isolated at all edges, abutments and columns to allow for movement due to thermal loadings; The manufacturers’ guidance for both the floor screed and the tiling must be followed to determine the minimum thickness of edge strip required to allow for expansion. Liquid DPMs gave the best protection but were more expensive. 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. Normally you would put a compacted bed of about 50mm sand under the DPM. The screed manufacturer agrees that their screed can receive an epoxy DPM. What is liquid DPM? Liquid DPM is a system that is used. Damp proof membranes (DPM) A DPM should be a minimum thickness of 1200g polythene and linked to the DPC with a minimum 100mm overlap. So, as money's too tight to mention round here, I replaced the leaking door with a cheap UPVc one. C. Using this latex based damp proof paint as a damp p. #2. 4. water will be likely to collect between the DPM and the old floor. The water got under the DPM and wet the slab and blinding layer. The bitumen adhesive also contained the same asbestos fibres. So he said to put the insulation on top of the slab. Do you need DPM under screed? What DPM is Required? If the hygrometer reading comes back above 75% relative. How to Damp proof a floor and walls using synthaproof as a damp proof membrane is shown in this tutorial. 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. 75m2 at 3mm, 1. Hi, just laying insulation on 1200g DPM and now looking for a cheap / simple VCL to lay on top of the insulation and under the screed. Then a primer like the one you have at 4-1 then if needed another coat at 2-1. Dig the oversite ground to whatever height allows your hardcore, insulation, blinding, slab,screed. apparently some of the screeds had a cold or hot bitumen in or under them. This can include timber floors, tiles, laminate flooring and carpet. 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. Also, even with 80mm screed directly over Celotex the sab can feel a bit "hollow". As a rough guide, laying conventional screed costs around £15/m2, increasing by around £5/m2 when delivered ready-mixed. Contractor wants to paint Sika Primer MD on top of the self leveling compound. (See FeRFA Guidance Note No. 3. If the applied DPM is still very tacky, this1. Depends where the UFH pipes are. However the tiler should apply a Primer before screeding such as StopGap P141. Your privacy. The builder wants to apply a DPM to the top of the slab before it is dry. When stripping the bathroom, the area under the bath tub was bare concrete, lower than the rest of the "black" floor throughout the property. Hi, I have an area of approx 6m by 3m on a ground floor extension which is block and beam construction, that I now need to insulate and screed to finished floor height. It is usually abbreviated to 'DPC', and in most buildings less than 30 years old, it consists of a DPM, which is a Damp Proof Membrane, an impermeable layer of material, most often a polyethylene or bitumen-polymer, that is laid in the bedding joint between two courses of bricks. Reaction score. This is why first choice is always strip footings. 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. As with the Kooltherm installation, start by ensuring a clean and level surface. Mot1 Sand/hardcore sub base. Where screed is laid on top of insulation, screed should have a minimum depth of 65mm. This barrier is intended to stop moisture passing from one to the other. with the concrete but the insulation. DPM’s can be applied to either a suitable blinding layer under the slab or internally to the top of the slab. The difficulty is getting the underneath concrete to have a flat surface at exactly the right level. Once set, you can then apply your screed flooring to the DPM base. Since that period I've take out the bitumen screed/dpm and been on the concrete slab since about mid February/March. DPM sheets should be overlapped by at least 300mm. Energy Efficiency: Concrete floors generally possesses lofty thermal mass & this may be. #1. Request a callback. you need to dig up the old concrete then lay a couple inches of sharp sand. We are in the process of having an extension built. California Country. g. The minimum sand and cement screed thickness would be 40mm as defined by the British standard. £12 - £16 per m2. Aug 18, 2010. Telephone: 0800 270 7837. #1. This will allow the screed to bond to the dpm. it could easily be up and down by up to 15mm. 18) Bricks. TB243. Laying new floor - needs DPM? dunroving Posts: 1,881 Forumite. But this all begs the question of why the hallway is so wet. Then a primer like the one you have at 4-1 then if needed another coat at 2-1. hours for Ceramics. 3. The dpm needs to be clean and dry. I am assuming its asphalt with a bitumen top layer, 10-15mm thick. Then once the screed is dry use a liquid DPM such as F-Ball Stopgap F77. DPC and DPM are lapped together at this stage. Don't think it will make much difference tbh, if you go the timber route use 22mm plywood instead of chipboard though. The Epoxy DPM 5kg is supplied in two 2. ; Stiffness: Concrete floors generally possesses adequate prudery & does not parry under the applied load which result in generating problems in non-structural elements, e. Spoke to makers of UFH system. The guy doing it tried to compensate by using more adhesive and most of the wood has. 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. 4m x 50m x 500g (200sqm) Black Polythene Vapour Control layer 4m x 25m (100sqm) TPS. It may be applied onto either a solid in-situ concrete ground floor slab or onto a precast concrete floor unit. 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. Liquid DPMs gave the best protection but were more expensive. 5kg multi chamber bags. They can therefore be laid under the DPM (the DPM is still necessary to prevent. Liquid DPM for Walls. Guarantees the early laying of all floorcoverings. Beam and block floors may need a levelling screed or grouting to ensure base level. Gaz, you need to change your message setting as I can't reply. Types of Liquid DPM. Once set, you can then apply your screed flooring to the DPM. (DPM) with joints well lapped and folded. Applying Damp Proof Membranes. I intend to consult BC but would like to educate myself before I speak with them Thanks in advance. You'll also need to take the dpm up the walls as well. Pro-Screed Gold is suitable for application over most underfloor heating systems. Before screeding can commence the area to be screeded must be made watertight to prevent leakage. 21m2 1. Used the primer neat as guidelines suggested. 49 per m2. Developer has quoted £3744 for approx. 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. Apply sand-blind base (this base should be level to within 5mm along any 3m straight edge). 1314. Roger Kenworthy on 2021-08-13 17:59:40: Question:Durability: A befittingly developed floor screed will outlast the else modules of the building. 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. #1. If its not right. I will post up a pic of the failed LVT in a minute for you! Screed seems to be getting damper. 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. #5. floating construction then a second "slip". No mention of reinforced concrete screed. Eventually I will rip out the old floor and replace it but I would like to understand (as much as possible) what is going on under it without taking it off. #2. Can you put DPM over screed? Liquid DPM is a system that is used over a base floor. Country. Go for the application of a surface DPM; The third option is however quite expensive, and could turn out to be more expensive than the screed itself. This essentially means that the screed has been laid in direct contact against the bottom of the aluminium door frame. This can only normally be guaranteed if its an new build or extension and most houses have been sold, inherited etc. CS Flooring. ← Installation of rigid floor insulation on ground floor concrete substrates to receive screed. Mapeproof One Coat can be used with underfloor heating systems providing the system has been fully commissioned as per BS8203 2009, Section 3, 3. The 40mm between the joists is about 0. 10 Sep 2021. P. He also saw hairline cracks in the top layer of screed in places. #1 CGN Screwfix Select andyscotland said: ↑ The concrete slab I poured for my utility room extension is slightly uneven - a small dip into the centre. 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. 17) DPM under slab. not bonded to the base – typically where a DPM is placed under the screed. Manchester • Member since 5 Jun 2015 • 64 jobs, 95% positive feedback. Curing Under Polythene 12 hrs 12 hrs Drying Time To Receive Finishes - from removal of curing polythene sheet 50mm thickness and 50% RH. 100 hardcore, 50mm builder's sand to blind, 1200 gauge DPM, 70mm insulation (Celotex, Kingspan, etc. Get it level then when it is dry and can screw through floor board into blocks. 3. Outside ground should be. 5m2 at 1mm thickness 1. (DPM) between the concrete and screed. Ok so I have drawn the attached image. What should normally happen is the inner course should be removed to concrete slab level. He intended to stick the floor to the bitumen DPM. Ideal for use where there is no functioning structural DPM (common in older properties). However the tiler should apply a Primer before screeding such as StopGap P141. TF. You can lay a fast track DPM (damp proof membrane) if your new concrete has had 2/3 weeks drying time. -markie-, Feb 10, 2020. Coverage: Approx 6 m at 3 mm thickness. Fast drying screed cost. Used the primer neat as guidelines suggested. The OPTIM-R VIPs should then be fitted from the corner following the installation instructions. 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. •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. you might just have a low spot along the old wall where the concrete meets the wooden floor. Suitable for use with underfloor heating and for encapsulating electric cable undertile heating systems. Fax: 0800 270 7368. Cutting open would void dpm so should be avoided. Guarantees the early laying of all floorcoverings. Ie work down from FFL. Can be used as a Damp Proof. But others are direct to earth, brick, rubble what ever. applications are suitable for bonded topping screeds. 250mu (1000G) Black Polythene Damp Proof Membrane (DPM) 4m x 25m (100m2/Roll) URN: 5004075. I would also gripfill under the plate to supplement the fixings if it were screed. Buy Now. When stripping the bathroom, the area under the bath tub was bare concrete, lower than the rest of the "black" floor throughout the property. 34. 6 March 2017 at 8:04PM edited 6 March 2017 at 8:59PM. Complete product range for installation, renovation and maintenance of wood flooring. 2. I would use 100mm x10mm frame fixings, especially in screed because it is weak. Pumped anhydrite floor screeds are not much dearer than ready-mix sand/cement, costing around £25/m3 (laid to a 50mm depth). Our expert team are ready to offer you the very best solution for waterproofing. 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 DPM should: have sealed laps of at least 300mm wide. For under screed use: Must have from ground up: dpm (under subfloor in this case), insulation, plastic vapour check, sand-cement screed or fibre-concrete. 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. Water is added to ensure a thorough mix and to aid workability. 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. In both cases the surface on which the dpm is laid needs to be as smooth as possible. The screed has water anyway, so a bit of ingress isnt an issue. Screed. Floor under carpet marked with chalk for wet areas. Figure 3: Concrete masonry foundation wall and concrete floor. Alan Jackson - Commercial Manager UK and Ireland - Gypsol. PermaSEAL Liquid DPM can also be applied to concrete floors below screeds. It still might not have a DPM under the floor. DPM sheets should be overlapped by at least 300mm.