Nick1c

I had to go for the 12mm board as it is the one that is certified.... It weighs a ton! It also looks difficult to handle as I can imagine it snapping if not fully supported when lifting it flat. We are having the house boarded out next week & I will ask if they would also do this as presumably they will have board lifters & are used to doing it. I assume these are the type of fixings needed : https://timco.co.uk/217228-cement-board-screws-countersunk-wafer-ph-self-drilling-exterior-plus-grey we are near the sea, should I be looking for stainless versions? If I wind up doing this myself (with help) is it a good idea to cut the boards in half to make handling them easier? Tips from those experienced in using this board gratefully accepted.

Me neither, but apparently it does what it says on the tin! https://www.owatroldirect.co.uk/product/floetrol/

A mate used Owatrol paint conditioner & raved about the finish he got.

Massive (f to c) is impressive.....but there isn’t much increase in light, overheating is increased, you loose thermal efficiency, useable room space & in our case it complicates weathering the cill. Does your view full the whole space? If not framing it with a smaller window might give as good or better an effect without the downsides & for less money. We have some large opening lights, the walls can create a fulcrum to overload the frame so we will need restrictors. Get the installation logistics sorted out & reliable fitters - we were delayed by 5 months over this.

Thank you. It sounds (as I thought) that they should be treated - the next question is take them off & replace with tanalised or paint with preservatives. I suspect the former ?. It’s not just 25mm batten as the rainwater down pipes are hidden behind it.

The frame of our house is being clad in a mixture of cedar & render, with some pressed aluminium details. The carpenters on site have been great, but over the last couple of days have been battening out one of the elevations with untreated softwood. We are on an exposed coastal site & they have been using stainless fixings. I have asked if this is a good idea & been told it will be fine as the cladding will (should?) keep it dry, it does however make me nervous. There are three options - leave as is, leave it up but paint with preservative or tear it down & replace with treated timber. Which of these is the sensible route?

Just on the point of getting this done. I managed to miss the joint filler - I thought it was board, FST, paint. It appears that it’s board (with an expansion gap at 10m), joint fill (50m2 per 5kg bag unless joints left open when it goes to 25m2), FST. My plan is to use a dry lining contractor to get the boards up, I am debating if the rest of the job should be DIY, done by the liners or a combination of me & the decorators. Any advice?

@Mr Punter we are going for flowscreed. Thank you for the idea.

Looks great. I share your stress levels & lack of joy. Hopefully it’s all worth it in the end...

Thank you.

@Mr PunterIt’s sounding promising.... how long does it take to dry? IIRC concrete is 1mm/day! Would the best thing be to lay a layer of thin ply over it before the boards (they are 85mm wide), or put the boards directly on the screed? Is it heinously expensive? We have 85-90m2 to do.

@Mr Punter Thanks for the idea. Would that work over the CLT? I am keen to keep the weight to a minimum as this wasn’t designed in from the start. What is the minimum thickness it could be poured? It would need to be min 25, max 55mm.

I have various things I am trying to achieve. The ffl needs to be 58-70mm above the CLT ‘slab’ to work with thresholds. We need a working floor to board out & decorate off. There will be UFH below in sand to give thermal inertia & take up space (we plan to use it for cooling as well). The engineered boards are also available in 22mm. As far as I can see the options Are 25mm batten with 12mm sub floor & 22mm boards or 18mm sub floor & 15mm boards. The 18mm sub floor gives a better working floor. I don’t think it is a building regs issue as it is equivalent to laying a floor on a concrete slab.

We are getting 15mm thick narrow engineered boards for our first floor. The structural floor is 160mm CLT, which is rock solid, it will have 25mm batten at 400 centres with an 18mm sub floor over them (the battens will have UFH pipe & kiln dries sand between them), the engineered boards will be glued to this. Is OSB adequate for this, or do we really need ply for a squeak free result?

I got through this afternoon - maybe they open after 8...

Resistant appear to be closed, does anyone know who stocks their 9mm fireboard? Thanks

Thank you @Temp thanks for looking, they are all 40mm high & we were looking for something as low as possible. The McAlpine trap looks very handy! @wozza they look like they will do the job with the McAlpine trap. We have a Mira flight atm with non-slip & like it, if you are finished in the next couple of months please let me know how grippy it feels.

We had planned to cut the slab to fit a flush tray, but I think a combination of soil pipe level, difficulty in doing it well (it involves cutting right up to the wall) & other things to spend time worrying about has beaten us....

@Mr Punter, thank you, I have emailed them. The problem may be that I need the protection in a horizontal rather than vertical plane.

It is a horizontal external surface that needs protection - the underside of the cantilever, the structural element of which is 160mm of CLT.

When we had the slab laid we put in drains for the shower trays on the rebar. This is 100mm below the surface of the slab, which is our finished floor. The location of the pipe means that we can’t have the drain under the shower head (it’s an 800x1600 tray) it needs to be central on the long axis, either to the side (preferable) or in the middle. This https://www.victorianplumbing.co.uk/mira-flight-level-rectangular-shower-tray would fit the bill, but the plumber thought the soil might not be deep enough unless the tray was raised 5mm. Does anyone know of a suitable tray with a shallow trap, ideally available with a non slip finish?

This is for the following build up (bottom to top): Cedar, fire board, phenolic insulation board (£££!), CLT. Space is tight due to window heights, 9mm board was specified. I have just googled MO boards, it appears that their use invalidates a number of structural warranties so I imagine that BC wouldn’t be keen.

Our timber frame has a cantilever which requires fire protection. The architect specified 9mm Supalux & I paid no attention to this until I found out how much it costs! I thought I had found a suitable replacement in https://www.fireboards.co.uk/ (naively thinking the clue was in the title...) BC won’t accept it as it doesn’t have the correct certification. Can anyone suggest (certified) alternatives?

I think I am going for a compromise - 38mm batten @ 538 centres, 10mm eps, sand/biscuit mix, 12mm ply. It gives me an optimal ffl, uses easily available materials (standard sized sheets of eps are hard to find, much easier to get EPS designed for EWI in 500’s) & a solid working floor. With 15mm engineered boards on top there will be 27mm of timber to impede heat transfer, but hopefully not too much. I am erring towards using sand as the benefit of dry mix in this situation isn’t obvious to me. Just seen that Wunda have opened!!

Due to a typo whilst ordering we have a Gaulhofer 2290x2270mm window which is surplus to requirements..... A quick look on eBay suggests that it is not a sought after item, exacerbated by the fact we are in (far) west Cornwall ? There are only two things I can think of as potential uses - as the mother & father of all windows in a garden shed, the problem here is that we are in an ANOB & would need planning, there would probably be objections, but on the up side if we got it it would give awesome views along the coast to the N & shouldn’t overheat the shed. - cut into a container, no planning needed but it would get less use & I am not sure of the effect of cutting a hole that size in one. Opinions on these ideas (or alternatives) would be welcome.