MarkyP

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About MarkyP

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  1. 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.
  2. 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.
  3. 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.
  4. 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.
  5. If I did mine again I would dispense with the thin coat. Baumit's base coat (star contact white) is a mesh reinforced NHL render with blended aggregates . Floated up it looked lovely and actually with a mineral paint finish would have been perfect.
  6. I have baumit thin coat silicate, it's very nice but this year has developed a few algae patches i will wash and scrub it this year which should clear it, there are products to kill the algae as well. But I think any modern texture finish will attract algae. A few thoughts on renders options: Sand and cement is very likely to crack, my renderer said he now refused to do it any more. Modern renders use mesh reinforcement which isn't used typically used with sand and cement. If you do use sand and cement, you don't have to use acrylic paint, consider the mineral paint option as well. Thin coat looks much better than monocouche. Mono is the stuff which is scraped back to very textured finish and uses exposed plastic beads. I think it looks horrible. Also the deeply textured nature makes it almost impossible to clean. Of the thin coat options you have three in terms of finish, acrylic, silicone and silicate. Acrylic looks plastic and is a cheap finish. Silicone can still be sheeney but less so. Silicate is my pref, it has a mineralic and matt finish. It is more expensive but coverage is vast from a tub so it's not really a big driver of the cost of the job (or shouldn't be). It has the added benefit of being over painatble with a mineral paint rather than others which would need a film based paint which wouldn't look good at all. Also be wary of the texture, the larger grain size changes the look considerably. I used baumit's finest grain af 1mm, I think it was called nanopor fine and it came up really nice. I don't like the typical 2 to 3mm grain texture finishes. Make sure your contractor knows what they are doing, thin coat is a very different method to sand and cement. Ask to see some reference sites if you can.
  7. I wouldnt worry about it. Your block layers will address it. as suggested above, a course of bricks and a cut block course on the beam would bring things back into line with the adjacent blockwork. Things might change as built so I wouldnt try too hard to plan mm perfect details at this stage. Brickies will be used to bringing things back up to course height with beams and lintels.
  8. I'm planning on walling off a section of garden but would like to if possible avoid using movement joints. The wall will be long, more than 10 metres for each run to square off a section of garden. No brickie yet but I know a few and with sand and cement I'm expecting to be advised to incorporate movement joints which I really dont like, especially in a feature wall like this. We're on chalk ground, soil only about 12 inches deep and then it's solid chalk so nice base to build on and I will run a decent footing. If the wall was built with NHL 3.5 rather than sand and cement might that stand a chance of accomodating any settlement or movement without joints? it's going to be fairly high, in the order of 1.8m to 2m, 9 inch with piers at suitable spacings. Lots of old walls around this way without joints (or cracks) but I wonder if the lime mortar in these old period walls is pretty weak stuff and 3.5 might be stronger and relatively more brittle. Anyone chanced lime without movement joints? thanks
  9. I opened an MKM account, I managed to get exceptional discount on timber and OSB but that was because the joiners I used were also a (big) customer and they secured their pricing on my account - I had them on a labour only deal with me supplying materials but when they saw my MKM quote for the timber they burst out laughing and a phone call saw it cut in half! othewise MKM werent much interested, was uphill getting decent prices on anything - insulation, blocks and so on, I gave up and went elsewhere. Had more luck with Travis Perkins, didn't open an account but got a trade card. With other suppliers, haggling worked often and just asking saw another 10% or 20% off their trade price but you need to be buying decent volumes of stuff, not dribs and drabs. Insulation I found best prices from the specialist suppliers like encon or the online discounters, builders merchants werent much interested in trying to compete and were better on timber, sheet materials, sand, cement, plaster, blocks, etc.
  10. Yes those are what your brickie would call lightweights. The labourer would disagree!
  11. Looks like others beat me to it, must type faster!
  12. I have none on my rendered EWi which was covered with baumit basecoat and thincoat silicate top coat. Baumit tech rep said movement beads are pointless unless there is an underlying structural movement joint, it's one of those old industry habits that hadn't died out yet. This is obviously one opinion but which they warrant - no cracks so far along an 18m wide single storey elevation. If the underlying structure doesn't have a movement joint then render will expand/contract monocoque with the substrate, if the substrate cracks then a movement joint only in render won't help, might be in the wrong place as no one will have told the blockwork where to crack 🙂 so the logic is if a movement joint is needed, put in render and substrate, not just one or the other. Talk to render supplier about their requirements, designers throw in movement joints in render by habit, may not be necessary. They are ugly, as are the plastic beads used with monocouche, my pref is silicate (mineral) thincoat, no joints or exposed plastic beads.
  13. I have none on my rendered EWi which was covered with baumit basecoat and thincoat silicate top coat. Baumit tech rep said movement beads are pointless unless there is an underlying structural movement joint, it's one of those old industry habits that hadn't died out yet. This is obviously one opinion but which they warrant - no cracks so far along an 18m wide single storey elevation. If the underlying structure doesn't have a movement joint then render will expand/contract monocoque with the substrate, if the substrate cracks then a movement joint only in render won't help, might be in the wrong place as no one will have told the blockwork where to crack 🙂 so the logic is if a movement joint is needed, put in render and substrate, not just one or the other. Talk to render supplier about their requirements, designers throw in movement joints in render by habit, may not be necessary. They are ugly, as are the plastic beads used with monocouche, my pref is silicate (mineral) thincoat, no joints or exposed plastic beads.
  14. There's scope for confusion over the terms used for blocks but generally lightweights in trade speak are aggregate blocks and they are not that light! They are medium density and would be fine for this application. Dense concrete blocks are for foundation courses and very, very heavy. Aerated blocks are to be avoided here, these are lightweight, brittle and suck up water like a sponge. Personally would use 7n medium density aggregate, I.e. what the builders merchants call lightweights. Confused yet? 😉
  15. Do you have a link to an example of such a stove, would be interested to look into the testing standard. Most stove manufacturers are greenwashing their products like crazy with the gradual awakening of public awareness to the problems of smoke pollution. I'd be staggered if a stove could genuinely in normal use achieve zero fine or ultrafine particulate emissions through the highly variable usage that results from different size, types and moisture content of fuel, lighting up, refueling, air supply, poor flue draw and wind, de-ashing the pan, etc. Likewise the efficiency, will vary through a burn cycle and isnt very controllable, you typically generate far more heat than you need compared with other domestic heating systems which can be tuned and controlled. I do appreciate the aesthetic and pleasantness of the wood burner on a cold winter's day and am a relucant convert against stoves having previously been a fan. But I think they are a lifestyle choice rather than an eco one. Dont underestimate the interior air quality impacts during a burn cycle as well - very high levels of fine and ultra fine particulates emitted each time you open the door to re-fuel creating a warm polluted fug in your sitting room for the evening, you could not fit the stoves and take up smoking a couple of cigarettes in the evening instead. 😉 *getsoffsoapbox*