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About MarkyP

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  1. does anyone know the rules on glass type and thickness for a juliette balcony? I've been getting some conflicting advice from suppliers. The balcony is face fixed to the frame of the french doors with a frame system, there is no top or bottom rail, the glass spans the opening fixed either side. The glass will be 1100mm high for the protection from falling regs but in terms of glass thickness and type I've been told 10mm toughened is sufficient and another saying 17.5mm toughened and laminated is required. The width of the opening is 1750mm. thanks
  2. I'm probably strating the obivous but use stainless screws otherwise you'll get a rust streak down your render face.
  3. you can get some fat EPS plugs but I treid them and didnt get on very well with them, they made a bit of a mess of the render and pull out resistance wouldnt be very high. my EWI is quite thick so came up with a way to avoid going all the way through, for things like lights I used long rawl plugs, drill a hole in render and EPS about 70mm deep, air spray to clear the hole, fill hole with squirty foam PU glue (mask face of wall first!), insert long rawl type plug watching for PU being splurged out, leave to set, then screw in with a relatively thin screw that only just bites the plug so as not to put too much rotational pressure on it. Worked well and the plug held without spinning and took a pretty strong fix but dont ask too much of the render. otherwise fix right through to solid substrate, with a plastic rawl plug the thermal bridge won't be too bad, barely worth worrying about. watch for point loads on the render face and dont overtighten
  4. it is the total thickness of the screed so, yes, measure insulation to top of screed regardless of pipework. If sand and cement screed then 75mm is about standard. Liquid pour is thinner. I used liquid at about 60mm, personally I find it a bit bouncy on the insulation and it doesnt have a completely solid feel, the kids thumping around can be felt through it. If I had my time again I would have gone with my 150mm concrete slab over the insulation and had the concrete laid to a decent standard of flatness/level and done away with the screed entirely. I havent done sums but reckon the higher spec slab finish is more than covered in the screed savings. Then I would have put finish floor over, or run a smoothing compound if it was a bit rough, then finished. Slab would possibly need some structural movement joints depending on what you want to put over the top of it.
  5. I used lightweight aggregate blocks, avoid aerated. Aerated is one reason why the volume builders dot and dab - to hide the cracks. Can you not widen the cavity to improve the uvalue if needed and add more insulation? Wet plaster best for air tightness and a nice solid finish, good to fix to. My brickie said he really doesn't like aerated, very high suction and mortar can dry before it's cured in summer. Cracking seems to be brittle nature of the blocks, they have standard compressive strength 3.6n 7n, etc, but weak flexural strength.
  6. I have vm zinc standing seam on my loft dormers, each dormer is clad in exterior grade ply with a membrane and standing seam over. Under the ply is a ventilated batten space, then insulation between and under the rafters. the fluffy stuff referred to earlier might have been OK if they'd used a 0.032 high density mineral wool like frametherm or rafter roll but if just standard loft insulation fluff at 0.044 then not ideal. Personally here I would prefer a combo of dense wool 200mm between and perhaps 50mm phenolic under rafter to get both a pretty decent u-value and a good decrement delay and sound insulation of the dense wool layer. But agree with others that ventilation under the metal would have been a standard detail unless very conciously designed otherwise. Some consideration of wind tightness of the mineral wool would also be a factor if a ventilated void was introduced. there are examples of fully filled build ups with no ventilation under either sarking or even a "non-breathable" metal roof but I think these are often with meticulous attention to airtightness detail and backed by warranted condensation risk analysis. Not sure the architect described here is in that bracket though. I have a hybrid roof - after much deliberation I have the south and south west roof pitches insulated with fully filled 150mm dense flex wood fibre with 75mm PIR under rafter, this is under OSB sarking and fully filled, no ventilated void under the sarking but ventilated counter batten space above the sarking under the roof slates, so there is lots of outward drying potential for any moisture that does enter the insulation layer, boosted by the solar gain on the slates which heat up in the sun. The roof pitches which don't get full sun are different, 100mm phenolic between rafter with ventilated void (eaves and ridge) under sarking and 75mm PIR under rafter. My BC inspector did take a few mins to understand my logic but couldnt see any issue with it, but he did say he'd never come across a roof with two different insulation strategies in opposite pitches before but he got used to my strange ideas during the project! This was a large loft conversion so I was limited in insulation depth by existing rafters. My trade off on the south facing pitches was a small drop in u-value for a large improvement in decrement delay to reduce risk of summr overheating. Those roof pitches without full sun I went for the best u-value I could achieve within the depth available to me without compromising room space too much so used phenolic and PIR.
  7. good to hear the below DPC is in the plan, this is a detail which seems to be more standard now, a few years' ago it wasnt. the builder will likely use a starter track or plinth at the DPC line. This is based on the idea that the DPC needs to continue through the EWI (I'm doubtful it is needed, EPS doesnt wick water to any extent but your builder will likely want it). Lots of discussion on this point on green building forum. But if you do have a plinth/starter track you might find a bead that will create a slight lip and still allow 50mm below DPC as well. Or you could consider wehther you need to mark the DPC at all and run 50mm all the way down, but I appreciate this might seem bold and your builder might not like it and sounds like you havent got much time to research it. I did use a bead at DPC but only becuase I needed to get the EWI done and planned to do below DPC later when I had the time to dig out down to the top of the footings so the starter track gave me a level base to work from. I'm actually planning my below DPC EWI this summer, 4 years on. if you need to backfill to bring the ground back to level (the plinth EWI should really good down to the footing) consider a strip of leca (clay pellets) - it's quite an insulative material and will create a further benefit in addition to the below DPC EWI and will help keep the area around the plinth EWI well drained and dry. Again check out GBF and search for "EWI & leca" there's an architect who posts with some really good ideas and experience with EWI. hope the admins dont mind the GBF plugs, EWI has been discussed there in great technical depth so is really worth a read.
  8. hmm, your window extension sills may not be big enough, this may be an issue. Mine were clip in and came in various sizes. Looking at the pictures (which may be deceiving), they look barely big enough for 50mm EWI, check that you can accomodate 50mm insulation plus 10mm adhesive plus 10mm (or more) render plus ideally 30mm projection for a drip. And ss above, 50mm really isnt enough insulation for regs unless you have existing, and in any case you really ought to do as much as poss while you are at it but the sills may be a constraint now. also ideally take out the soffit and run the insulation up the face of the wall to the underside of the roof (be midnful of ventilation though), between rafters/joists such that it can meet the loft insulation. If not you get a cold spot at the top of the wall and window heads where there is no insulation. it will mean running new soffit or refitting cut back original sofft but again an important detail most installers wont bother with as too much trouble. if the below DPC EWI seems too much to contemplate at the moment, the builder will run PVC starter track along DPC in all liklihood anyway so you could do the below DPC EWI later when you can face digging it out to the top of footings and installing. if the renderer is good get his number and see if he fancies a little side job to come back and do it later. If you end up with 50mm EWI then think about a drip or bellcast bead as you will not want less than 50mm below DPC and will need a drip detail of some kind to create a small overhang at the join.
  9. I've done EWI to my bungalow renovation and a few things to consider. In my view the best insulation choice is graphite enhanced EPS. However, unless you have existing insulation in those walls, 50mm isn't anywhere near enough to meet regs which you should aim to better in any case. If your builder proposed Jablite then I think this will be EPS which is a start however the spec sheet doesnt say what type - you need to check they are using an EWI grade EPS sheet, this will be grey coloured (graphite enhanced) and more insulative than the white stuff. It should also be from aged blocks which are dimensionally stable, again EWI grade will be such. Even if you do have insulation in the walls, go for as much EPS as you can accommodate with your eaves/verge overhangs. The thicker the better. 50mm isnt very much at all and adding thickness isnt the main cost driver here, EPS is pretty cheap. I'd go for at least 120mm or more. check out green building forum, search for "DIY EWI installation thread" to read all about my install. i did it myself and spent more time than I care to admit researching it! things to watch out for - - make sure the installer foams the joints in the boards. If they pug them with adheisve this is creating thermal bridges and is bad practice (but very common practice!) - ensure they use branded, EWI grade EPS (I used kaycel) - ideally they should use thermally broken fixings and adhesive, the fixings are recessed and have a insulation cap, really neat (see my thread on GBF) - avoid an aluminium tray at the DPC if you can, plastic is better and doesnt create a cold bridge. - you dont need to break the insulation at the DPC contrary to building folklore it really wont matter or create issues but your installer might not agree. You could run run the insulaton right down to the top of the footing. Alternative is to break with a plastic plinth bead at DPC and run a course of EWI under the DPC level to the top of the footing. The aesthetic of the different DPC levels will be a fiddle but how you detail the below DPC insulation will be a factor. - through colour render isnt my favourite, I prefer thin coat with mineral silicate finish. I used Baumit star contact white basecoat and nanopor fine finish. - think about where you might need to mount rainwater downpipes. You cant fix into EWI, you can put timber grounds behind the insulation to screw into, or fix right through into the underlying wall - frameseal beads for windows are really neat, check if they use these if not sugges tthey do, rendering up tthe window frames is scruffy and will need to be siliconed to create a weather seal - EWI is a great solution - will make the house much warmer and the insulation is inherently wind tight once installed and rendered (unlike brickwork and cavity fill)
  10. thanks for the link, interesting that we have a similar issue to that discussed there by @HerbJ with a sloping site and struggling to see how it might all come together. We've lined up a few outfits to come and quote to give us a design so we'll see what they have to offer.
  11. I've rather left the outside of my project as something to worry about later, but later never seems to come and my DIY ethic means that it will be 2030 before I get around to the garden if it is left to me (I'm still up to my eyes in work on the inside). I dont want to landscape or design the whole lot, just a hardwood decking area and a larger stone patio area to create an outside living space which we really need. I did initially think why would I want to pay someone to design a decking area and some paving. But actually the area we want to landscape here is quite large and with different sections and is sloping so there are changes of level to think about, walls, steps and 3 entrance ways to cater for - large kitchen opening and 2 sets of double doors. Also need to think about the aesthetics which might beneift from someone who has done this before. In a nutshell I am coming around to the idea that having someone do a design and provide some drawing and I can then use a few sub-contractors and give them something to build to with me perpaps doing the initial digging out and footings for walls. I dont know whether to try a few local garden design outfits or perhaps the architectural tehcnologist who did my drawings for planning and regs. Interested if anyone has had any experiences good or bad.
  12. In theory the basecoats and tops coats would be interchangeable but the manufacturers will have tested and warranted them in combination. In practice my view is the warranty is all but useless as the supplier and installer will point fingers at each other. I did an EWI training course and the provider explained that a supplier who will be nameless would always find an installation fault or some other problem than the product itself - thickness of render basecoat, lack of drying of basecoat, structural movement, lack of adequate primer, too thick/thin top coat, too rapid drying of top coat, lack of mesh re-inforcement, etc. All these install faults may be real or not, but as the customer I could imagine it being something of a battle to estalish liability. personally I think these manufacturer warranties are pretty much worthless but where they supply a base, primer and top coat as a system, you would expect that they had tested and developed the products together so all things being equal, you'd probably take them all from the one supplier. I used Baumit for base, primer and top coat, but that was because all three made for a better deal commercially as much as anyhting else. they did offer good pre-sales and on site support to my installer, as well.
  13. Mine is over 120mm of graphite EPS EWI (plus existing 75mm mineral wool cavity) so the render layer doesn't get much benefit of heat from inside the house. My basecoat was left during the first "beast from the east" winter a couple of years back- days at zero to minus 5 or lower. I'm also on a very exposed elevated site, sideways rain and strong winds . I wouldnt leave base coat indefinitely but I don't think there is much difference in thin coat vs mineral paint as base coat finish, they are a colour finish and water proof layer, just one has some aggregates in the mix. Cracks are an issue of basecoat failure.
  14. Most exterior masonry pain is acrylic based. It coats the surface with a thin film. Think sandtex and the like. Mineral paint chemically bonds to a mineral substrate so won't ever peel off. But it needs a mineralic substrate to react with, it otherwise behaves like a regular paint over acrylic or previously painted surfaces. I suspect the same over silicone. Keim is a leading mineral paint brand, expensive but good stuff.
  15. The silicate thin coat render products are i would guess basically mineral paint with some aggregates in the mix. Lime Green do a base NHL render and told me their finish coat is a mineral paint, same tech as Keim, etc. I don't know how strong the baumit base is, it's a lime cement hybrid, probably fairly tough stuff. We left our base coat exposed all winter as it was too cold and wet to risk applying the finish thin coat. It was fine - no cracks or frost damage and got soaked and frozen repeatedly.