If in the screed then no problem with this. com. Hi, I'm doing a kitchen modernisation in my ex-Council house which was built in 1947. Applying Damp Proof Membranes. That seems to be the recommended practice but I'm not sure how many bother with the one on top. Depends where the UFH pipes are. Staffordshire. The old adhesive should of been removed. Care must be taken to a) ensure there are no holes or tears in the sheet that could allow. the cut. Country. The guidelines state that a damp proof membrane that is placed under the flooring should be around 1200 gauge and constructed of polyethene. DPM over a new underfloor heated screed, the heating system must be turned off 48 hours before application. There is a membrane underneath the concrete slab which has been poured and it comes up and meets the dpc. 5m x 100m, 2m x 100m, and 2m x 50m. ARDEX DPM 1 C may be used if; 1. DPM sheets should be overlapped by at least 300mm. The specific liquid DPM system will depend on the type of substrate or screed. Energy Efficiency: Concrete floors generally possesses lofty thermal mass & this may be. The screed manufacturer agrees that their screed can receive an epoxy DPM. Step 3: Lay the watertight membrane. Perfect for new builds and refurbishment projects, our range of floor insulation products include optimum peformance OPTIM-R Vacuum Insulation Panels (VIPs) with an insulating performance up to five times better than commonly used insulation materials, and. 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. The best example of insulated floor thickness is 100mm (insulation) + 60mm (screed) + 20mm (floor tiles+adhesive). Needs a dpm under it and i normally put one on top too - stops you accidentally sticking the boards to the insulation. If under the screed this is normally a polythene dpm so the screed is then an. steve have you checked the level of all of the concrete floor. I think underfloor heating would work if you layed DPM, insulation (as much as poss) woodchip flooring and don't use a screed. Hi All come across this forum and would really appreciate some assistance. Location. Had a look at the pics and IMO no dpm under the subfloor. DPM (1200 gauge visqueen) Old Concrete Slab. They can be used under resin screed finishes and are applied in thinner sections than standard cement screeds. blocking/nogging for support of plasterboard 43mm x 38mm. sandwiched under the screed, were also common and usually in liquid form, e. Fit a damp proof membrane as above, then lay a separation layer. The membrane is manufactured in standard 125mu, 250mu, and 300mu thickness and in roll sizes of 1. Some houses in early 70s don't have a DPM as I've found out over the years. Under ambient conditions, PALACE 1-COAT DPM is ready to receive a smoothing compound as soon as 4 - 5 hours after application. Many can be used over a variety of existing uneven substrates, using gravity to allow the latex mixture to self-level. For unbonded and floating screeds, a DPM may be specified between the base slab and the screed. 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. British Standard (8204:1) says minimum 65mm for domestic floating. #2. My work will be (in order of layers): 1) DPM 1000 gauge with joints taped with Polythene joint tape. 15 Feb 2015. Other benefits. They left the bitumen glue on the floor (apparently, this is often ground off before laying screed), and applied PVA to seal the bitumen, which also contains small amounts of asbestos. Once set, you can then apply your screed flooring to the DPM base. Aug 18, 2010. £51. The damp proof membrane (DPM), normally 1200g polythene or radon barrier, should be laid over the blinding,So not convinced glue down is right. In order to prevent damp rising through the concrete floor and causing issues, a DPM should be used under all final floor types including wood flooring, laminate, vinyl and floor tiles. Ltd. 100m² per roll. £12 - £16 per m2. 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. Dig it all up (Its possibly up to 50mm thick) Then lay DPM/Visqueen sheets tanked up the walls and lay new concrete or use an epoxy liquid DPM tanked up the walls and lay a deep base screed. If there was no dpm I would suggest a uniformal distribution across the whole floor. 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. For rafts, DPM and screed must be on top of raft and screed must be at least 65 mm thick. TB243. Screed & Insulation. All waxes or sealers must be removed, and patching/leveling or embossing must be brought to a flatness of 3/16” in 10’. LKAB Minerals +44 (0) 7966 651006. 5kg multi chamber bags. The screed will be only ~50 max (not yet dug any up). 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. Visqueen are recommending we don't use Ecomembrane but instead use Visqueen Vapour Barrier if we have a DPM under a screed with UFH heating, because it doesn't have folds in it and this helps prevent cracks in the screed. I moved into my new build nearly 2 months ago now and am having quite a few issues. 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. Ball and Co. you might just have a low spot along the old wall where the concrete meets the wooden floor. Non-structural floor screeds shall be adequate for the location and intended use, and provide a suitable background for floor finishes. The Epoxy DPM 5kg is supplied in two 2. Alan Jackson - Commercial Manager UK and Ireland - Gypsol. 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. Prime and reapply , then screed to level and tile. Pro-Screed Gold is moisture tolerant and can be used under and over DPM’s. We provide a range of solutions including DPM screed, flooring primers and more! We are also radon barrier suppliers, making us perfect for all your needs! Call: 0330 223 2364 ; Email: estimating@cscscreeding. 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. Cement screed. Walkable in 6 hours. . Beam and block floors may need a levelling screed or grouting to ensure base level. 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. you can then lay your celotex or similar then concrete then screed or dpm concrete insulation screed . 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. 11 Protection against heat, and BS 8204 Part 1 2003, Section 6. 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. This told us tha. 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. Should I lap DPM under or over Dpc then celotex, then another DPM lapped up the wall with. . Country. Use 1000 gauge or thicker – ideal for this is the polyethylene use for the DPM under your concrete subfloor. This barrier is intended to stop moisture passing from one to the other. 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. The DPM should: have sealed laps of at least 300mm wide link with wall DPCs to form an impervious barrier to. 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. Request a callback. Price: £4. now what i know of screeding is very little but i can do a good job i have used in the past chicken wire under floor insulation, slurry coats on concrete etc but the guy who wants the job doing is going on about a barrier around. 20)Reinforced concrete floor. I would say the screed was. 21) Timber block. or email. Just lay a couple of good thick beads on the dpm and stick it to the wall. i'n not farmiliar with wickes dpm and the primer used for professional (if you like) screeds is neoprene. This was due to a neighbour redirecting the water from his gutters. If the DPM is still wet you should have not tiled over. Seems fine so far. Relative Humidity: The moisture content or relative humidity of the atmosphere plays is a major factor that affects the drying time of the screed. 5m2 at 1mm thickness 1. 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. 1200g dpm. New-build install: £50 to £75 per square metre. 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. 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. The specific liquid DPM system will depend on the type of substrate or screed. A full sheet DPM is 250 microns (1000 gauge) thickness or above. It is essential that this. 1955 house, recently moved in and presuming no DPM under concrete slab. 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. C. Suitable for most construction damp proofing requirements. 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. rev 2023. Hello, hoping someone can help. 5mt x 4mt rolls | £ 56. Our costs are ballpark averages – get a local tradesperson to quote now. Property is mid 1960s, solid ground floor. 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. 00. Nice. Checkatrade offers the following guide: Electric underfloor heating cost. It is also recommended that light reinforcement be used. Customer asked me how did they stop rising damp before the Dpm sheet was used and it made me think ( that hurt ) . It is not. ARDEX DPM 1 C may be used if; 1. blake floyds; 23 Jul 2009; Building; Replies 3 Views 5K. #1. This essentially means that the screed has been laid in direct contact against the bottom of the aluminium door frame. you need to dig up the old concrete then lay a couple inches of sharp sand. Checkatrade offers the following guide: Electric underfloor heating cost. As a rough guide, laying a conventional sand/cement screed costs around £15/m2, increasing by around £5/m2 when delivered ready-mixed. Country. 3) 50mm - Screed with Concrete Fibres, on top of the insulation boards. The concrete slab was usually 100 to 125mm thick. would it beneficial to change the floor structure to incorporate circa 250mm of eps insulation under the concrete slab, instead of the 150mm pir above. However, when I hammer-fix the battens to the concrete I'm going to punch holes in my DPM. The DPM should: have sealed laps of at least 300mm wide. 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. 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. A latex based screed isnt as affected by moisture/damp as a water based is. 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. Damp proof membranes (DPMs) can be used to help resolve damp issues which already exist or to avoid damp or moisture problems in. 25 Apr 2010. Labour costs. Sunny Hampshire. Damp Proof Membrane is intended for use within solid concrete floors to prevent the rise of moisture or damp through structure flooring. #2. What should normally happen is the inner course should be removed to concrete slab level. Preparation is key with these coatings and the substrate must be sufficiently clean and dry. 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. Fig. Once set, you can then apply your screed flooring to the DPM base. 4 so you have around 1. 1 left. Guide Underfloor heating A guide for house builders NF71 NHBC Guide to Underfloor Heating 2nd draft RH. Let’s hope you have a good water table as that’s the wrong dpm used. 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. The oversized DPM was instead lapped with the DPM that was placed under the screed. Hull. Should I lap DPM under or over Dpc then celotex, then another DPM lapped up the wall with 25mm up stands. With the number of planning applications for basement extensions rising by 183% according to research by Halifax, tilers need to be aware. 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. Note though that this will raise the floor level by 75-100mm (depending on the insulation). Only one coat though. 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. A Damp Proof Membrane or DPM is a waterproof barrier that’s introduced between your sub floor and your wood floor. The buildup is. Sealing a patch of DPM around its edge to the old is easy, just use silicone goo. This is done to maintain energy efficiency and prevent. It should accommodate 0mm to 5mm (or thereabouts) It will cover an area of 26m2 (4m x 6. No need for double DPM. 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. . Alan Jackson - Commercial Manager UK and Ireland - Gypsol. 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). Acknowledgement : The Concrete Society. The 40mm between the joists is about 0. This will give calculated u-value of 0. Alternatively, a mechanical key for the subsequent application of levelling materials such as a screed can be created by sprinkling fine washed sharp sand or kiln dried graded quartzFintan has travelled to Baden Württemberg in Germany to study passive housing and sustainable energy technology, gaining significant knowledge regarding the use of natural insulations in timber frame and solid wall constructions. Developer has quoted £3744 for approx. 100mm **concrete base*. Information ARDEX DPM 1 C. Tramex reading at the time of vinyl removal was 3-4+. For this, a metal mesh standing with plastic pillars ( (feet) will be laid before the concrete is. Small hole dug through 2" soft sandy concrete to reveal hardcore and soil. 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. e. 22 August 2019 at 10:27AM. hot bitumen, or cold bitumen in solution. of the screed should be checked by the Main Contractor. #3. (This is assuming its a slab insulation. Diagram B39 - Proper sealing. Any advance on laying 75mm kingspan directly on existing screed with DPM beneath, then laying 18mm T&G moisture resistant chipboard. 16) Concrete slab 300mm. Lay and level the concrete slab, allowing sufficient time to dry out, as per BS 8203. You are talking about a solid concrete floor which has to be on load bearing stable ground. 1. It is advisable to incorporate a light mesh within the raft for reinforcement. It should be waterproof to prevent any rising damp getting through. Types of Liquid DPM. Do you know whether the fitter did any kind of damp proofing under/on top of the screed? And have you had any damp problems since then?Screeds – general. 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. Your privacy. DPM sheets should be overlapped by at least 300mm. A Damp Proof Membrane or DPM is a waterproof barrier that’s introduced between your sub floor and your wood floor. 1314. Size is 4m x 4m. Replacing over half of your floor will mean you’ll have to insulate to at least 0. Im not quite sure where my DPC should be going. The old floor tiles do contain a small amount of asbestos ( Marley tiles etc. USES For priming, consolidating and sealing of: Absorbent and non-absorbent sub-floors, consolidat-ing weak cement screed and isolation of old adhesive residues. DAMP PROOF MEMBRANE. will come down and meet the insulation under the screed so the screed is totally floating. water will be likely to collect between the DPM and the old floor. 2 of the internal walls in the older building will be left as bare stone,. m10 cement based levelling and wearing screeds 160 m12 resin flooring 163 m13 calcium sulfate based screeds 165 m20a plastered coatings 166 m20b rendered and roughcast coatings 169 m21 insulation with rendered finish 172 m40 stone, quarry and ceramic tiling or mosaic 173 m42 wood block composition block and mosaic parquet flooring 1763. if there is insulation also under the screed i. g. The Epoxy DPM 5kg is supplied in two 2. #2. Use 1000 gauge or thicker – ideal for this is the polyethylene use for the DPM under your concrete subfloor. DPM is usually below the concrete, then the insulation, then a polythene sheet to stop the insulation floating as the screed is poured. I would guess, that a standard mix was used, as that would be cheapest, so could assume 1mm per day, but that`s why a test would be needed. if your DPM were above the concrete, the uFH would be heating a large damp lump of concrete. 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. Like a lot of houses of that age, the ground floor is bitumen/asphalt over a concrete screed. . Pumped Anhydrite Screeds. We used the Ultra Floor system, Ultra DPM-it,. hallbeck New Member. 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. LKAB Minerals +44 (0) 7966 651006. 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. 15) DPM under screed. The rest of the floor will be as follows (top down); flooring. For an excellent balance of. 13) Polypropylene. Screed above dpm. Then a DPM on top to avoid them floating in the screed. The tiler can then latex or screed over the DPM. We have a few options: 1. 2. 9% screeds been down since February. WoodYouLike. The OPTIM-R VIPs should then be fitted from the corner following the installation instructions. 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. ) chrysotile (white) asbestos fibres. This is why first choice is always strip footings. • GG300 – 300kPa. Mastic Asphalt – this is the earliest form of liquid DPM and is usually laid on the top of another membrane or a fibreglass surface. 001 Ardex Australia 201550mm insulation would be better than nothing be it under screed or timber. is that do-able? if so, can I just run the DPM 1 course above DPC? it's too late to tuck. The floor is concrete slab, 100mm Kingspan PIR, DPM and then 70mm screed. A floor screed is usually a cementitious material made from a 1:3 or 1:4. 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. Don't think it will make much difference tbh, if you go the timber route use 22mm plywood instead of chipboard though. This generally takes 1-2 days, depending on the thickness of the floor screed. Our Liquid DPM can be used on walls under a render to create a flexible waterproof layer. With the number of planning applications for basement extensions rising by 183% according to research by Halifax, tilers need to be. 4,049. 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. Out of the 7sqm of floor i guess about 1. 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. doors. hallbeck, Jan 26, 2010 #5. 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. You can lay a fast track DPM (damp proof membrane) if your new concrete has had 2/3 weeks drying time. This allows for the full 5kg or just half to be mixed at once depending on the area to be covered. BBA certified - third party accreditation. Doggit. 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. Guarantees the early laying of all floorcoverings. 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. DPM is normally used in floors. 3. Hence we always say DONT apply a surface dpm to a subfloor subject to rising damp. 17 May 2010. Yes. Screed on top of slab is cracked/crumply/blown so that’s come off and now down to the concrete. Figure 1: Concrete floor slab and integral footing. POLYTHENE DPM & VAPOUR BARRIERS. 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. Choosing the solid concrete ground floor insulation is important for any project. 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. I see some under the wood bearers, so hopefully this will keep the base dry. Discussion in ' Builders' Talk ' started by barnjules, Jan 30, 2017 . For a self-levelling screed a system such as Flowcrete UK’s Hydraseal would be used. J. 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. floating construction then a second "slip". 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. The liquid membrane forms a strong seal and makes a permeable layer to enable moisture to evaporate off. The main drawback. Our self levelling compound, or floor screed, is available in a wide range of varieties for a multitude of floor installation applications. 21. Well, when I did exactly this on my lower retaining wall - a mere footandahalf high - I lined the back with DPM, the stuff you put under screed to seal yer floors from rising damp. Screeds are covered by BS 8204, Screeds, bases and in-situ floorings, (2004). 0. 5kg multi chamber bags. Also there MUSt be a DPM under the screed to stop any substrate moisture coming up from underneath as a result of heating. 25W/m 2 K to meet with building regulations, even if you didn’t plan to. 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. Dig the oversite ground to whatever height allows your hardcore, insulation, blinding, slab,screed. 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. Packaging: 25kg bags. Fig. Ok so I have drawn the attached image. 34 dpm under insulation and screed. When I origianlly pulled it up it was damp under the bitumen screed/dpm around some cracks in the slab (guess trapped moisutre was trying to escape there), it dried in about 10-15 minuntes and has been done dry and. As an alternative to under concrete or surface damp-proof membranes a damp-proof membrane may be sandwiched between the site concrete and the floor screed, as illustrated in Fig. Brian shows how to correctly fit a Damp Proof Membrain - DPM in a new build houseLink to the T-Rex tape Website Http://bodgeitwithbri. You also should have removed the vinyl tiles before priming and screeding. Your builder or yourself should have laid dpm under the dpc course on top of the hardcore Base laid on soft building sand . In addition to the damp proof membrane (normally a 1200-gauge polythene sheet below the insulation), a 500-gauge polythene VCL. Reinforcing concrete. 1 or just a bit less. 67. Use polyethylene sheeting to create a waterproof membrane to ensure that there is no leakage of the screed when it is pumped in wet. 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. 14 m-1 P/A and use of edging insulation. 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). If there is an operational DPM beneath the concrete you don't need one on top. 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. Liquid DPMs gave the best protection but were more expensive. Said he'd provide a quote but didn't come back to me. TB243. Express Liquid Screeds Limited. However the tiler should apply a Primer before screeding such as StopGap P141. This will leave bitumen (ironically) glue residue behind which is a problem to remove I believe - and must be completely gone. There is a small section along the chimney where. Reinforcement to Suspended Floor SlabsClick and buy N-Virol Superseal Plus Damp Proofing DPM Paint which an be used for several applications including damp walls, floors and on basement walls. Epoxy DPM itself (the actual product epoxy) wont fail once set. 28. The total floor insulation cost will have two elements – the cost of materials and. 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). 100mm c35 concrete with mesh. 5kg multi chamber bags. I would use 100mm x10mm frame fixings, especially in screed because it is weak. 50mm C&S (1:4) screed towelled smooth.