Search the Community

Apologies in advance for the dumb question. I'm getting a wall rendered over existing and one of the people quoting suggested pinning render mesh to the existing render. Stupidly, I forgot to ask him what this meant so now I'm curious. What pins are used and how are they applied?

Hey, I am building a new home with basement. My structural engineer has specified a 400mm thick sl ab, and the slab reinforcement is 100% H20 rebar. This is to support a 5 bed property over ground, 1st, 2nd floor, meaning the basement walls are structural. I assumed that the slab would have been mainly made up of steel mesh, and H20 starter bars for the walls. Instead, over a 240m2 base there will be 8259 linear meters of H20 top and bottom. The wall starter bars are specified H25. Does this H20 and H25 sound overkill? £16k + vat worth of steel in the slab alone. If you know groundworks well, I would be interested in your thoughts Thanks

We need to put some insect mesh on our parapet roof edges. Got to allow ventilation into roof but stop the insects. Soon the parapet will be covered by a Sarnafil roof covering which will overhang, still letting ventilation come up but effectively weatherproofing the mesh. What sort of mesh would you use? Stainless steel (expensive but longer lasting) or plastic (cheaper but will it last?) or PVC coated woven fibreglass? Or something else? And will a staple gun do to fix it - if so, any clues on staple sizes? This is Saturday's job so going to need to order some stuff pronto. Sorry no photo - too dark to take one now.

Been a bit quiet on BH as I've been busy elsewhere - rectifying Bodgit Builder's attempt at laying my concrete floor. I started a thread about that here: Having taken ages to lay my circa 300mm of EPS and mesh-tied UFH pipework, I was keen to get a professional in to get me back on schedule and pour a flat, level concrete floor. No top layer screed. A few local companies quoted, one stated that they could not guarantee the pipework so I didn't go for them and the others I had simply had no faith in. I ended up contacting a local architect's firm and they recommended I contacted some of their regular builders. A couple were either too busy or candidly said that the job was not for them. The other chap came and quoted me for the job with the assurances that he could get a level floor finish. As it was a retrofit internal slab, it took him 2 days to pump 150sqm @100mm depth. On day 3, I inspected the 'finished' floor, and it was nothing but flat. I could really feel the varying levels of the floor by just walking around - I didn't need a level to tell it was way out. I also noted that the datum at the big slider was approx 20mm below where it should have been. Having contacted Bodgit Builder he duly came round and he agreed he would come back to grind down and high spots and fill where necessary with self-levelling (even confirmed the latter in an email). Prior to the day of his grinding, I scraped away at some of the high spots to discover that there was only 1-2mm of concrete/latence covering the UFH pipework. He'd obviously had issues with the mesh/pipework raising to the top (yes, I had fully purged all the air out!) and rather than doing his utmost to push the mesh down, he'd just decided to 'cover' the raised pipework with a bit more concrete. He either didn't have any idea that this would impact the agreed floor height or didn't give a damn (and must have thought I wouldn't notice!). He did admit that he'd had an issue with this section of the floor and asked me how I wanted to have it rectified. I duly informed him that this loop of pipework would have to be dug up and re-inserted at the appropriate depth and re-covered. He spent 2 days grinding high spots with little impact. Moaned at the cost of the grinding blocks and started making excuses as to why he couldn't make it back until a few weeks time. In any case, after nearly 6months later, he has not returned (as I expected) and have had minimal contact (just a few lame excuses) as to why he hasn't been able to rectify his work. Spot the issues: Is that a bit of mesh sticking through the floor? Yes! Luckily in the corner where the kitchen cupboards will be (no UFH). Easy to cut out in the end. Bit of a hump (approx 30mm difference over 500mm) Door threshold? what door threshold? Maybe should have gone for a concrete floor finish! Nice high spot by the door. Inward opening door too. May either need to skim off 30-4mm concrete (risk revealing more pipework or may have to raise the whole door frame - luckily it's timber framed at this section) Bit of a 'dump and dash' job Not that clear here, but concrete is well abobe the red mark (AKA the "do not go above here" mark). Yes Bodgit was wearing specs, but obviously didn't go to Specsavers. Can't get worse than that? Luckily I've found a local flooring company who also have experience in grinding, so they've been busy sorting out the high spots (only to reveal a further 3 rooms that have pipework that needs to be dug up). They didn't want to attempt doing that, and rather than risking getting in another 'professional' I've resorted to doing this myself. Intricate work that few builders would get right - not without damaging my ufh! Various UFH pipes revealed when skimming off the first few mm of concrete: Slab above probably needs another 20mm taking of in order to hit the original datum, so hopefully no further pipes to be found! First set fully revealed and ready to be pushed back although one has been damaged when they skimmed the top. You can just make out the grey inner lining: So this bugger needs to be replaced as the grinder's kinda ground it out. So how do you replace a section if the coupler's aren't supposed to be buried??? "16mm Repair coupling for use with Wunda 16mm Pert/Alu/Pert floor heating pipe, when a repair is the only option. This fitting must be fitted in a clearly accessible location and under no circumstances be buried in screed or concrete." https://cdn.wundatrade.co.uk/wp-content/uploads/2017/08/T03-Wunda-Generic-16mm-nut-and-insert-repair-coupling.pdf Tape coupler with self amalgamating tape? Obviously will fully need to pressurize before I cover. I'll need to add the couplers on the straight sections as adding on the bend will just compromise it all. Should I leave a small void around this join in case I need to access it? Or box in around the coupler and fill with a weaker mix in case I need access in future years? It's in a corner in the kitchen with no units going on top, just the laminate flooring. At least I'm not the only one with this issue: Once the flooring company and I have completed the required work, I'll be looking to get a PI to locate Bodgit Builder as he's started moving house which isn't much use when you want to take the bar steward to the small claims court. Lessons learnt: Don't always trust recommendations! Do it yourself! Pay particular attention to the end and loops/mesh in the corner as these are the areas that seem to rise up when pouring It's not the end of the world, there are things much worse in life that will/can piss you off, so don't let the bar stewards get you down.

Just interested to see what people have paid for their exterior render as some quotes seem extortionate. Our system will be a thin coat fully embedded mesh onto a render board. TIA

I've just about completed my slab insulation for my extensions (EPS + Celotex) and old bungalow (EPS). I've used 25mm of EPS perimeter insulation and will probably stick on the 8mm roll stuff that I will get from UFH supplier. So I'm just about ready to get my 2.4x4.8m mesh sheets into place (will have to cut most of the buggers in order to get through door ways. Luckily I should at least get them through the larger sliding door at the rear. The plan is to have UFH cable tied to mesh and then have a wet mix concrete pour. No final screed! Before I start cutting and laying them, i have some questions: 1) How much overlap should I have? Is one 'square' overlap enough? The mesh has 200mm squares. 2) How far from the walls should I have the mesh? I know there should be some distance and I think I read somewhere 150mm? 3) Tying wire. As it's just a case of keeping the mesh in situ whilst concrete is being poured, would cheapo galv wired be sufficient rather than defacto tying wire? e.g. https://www.toolstation.com/shop/Landscaping/d130/Wire+Fencing+%26+Tools/sd3333/Galvanised+Straining+Wire/p40640 4) Should I continue the mesh through doorways? 5) Not mesh related, but if I am supposed to cover the celotex top layer (in the extensions only) with a poly sheet (vapour barrier) or should I use something more heavy duty like a DPM? (I have the DPM/radon barrier in already but further down the layers. My only concern with the lighter vapour sheets is that it is more prone to being punctured / ripped with the mesh (I will be using chairs) and people (i.e. me!) repeatedly tripping over the mesh. 6) I intend to tape up the celotex joins (not the EPS sheets). Can I use any tape to do this or need the foil type tape? Thanks in advance.