Hannah82w

We recently had our main living area floor tiled, having turned the underfloor heating pretty much off before tiling commenced (the screed was poured 10 months ago and UFH heating commissioned 6 months ago, was on and gradually increasing temp over about 6 weeks until the warmer weather arrived and then back on again recently bringing the flow rate temp up to a max 35 degrees). During and since tiling, the flow rate temperature in the actual UFH pipes seems to have held at about 12 degrees and the ambient air temp around 15 degrees. Advice online suggests keeping the temperature at about 15 degrees during and after tiling (I assume this is ambient air temp, which it has been) and not bringing the heating back on/up for 7-10 days (we're giving it at least 14 days), but when you do the advice talks about bringing the temp up to no more than 27 degrees and to do so in 5 degree increments. Presumably this is also the ambient air temp, so can I also assume that you would bring the flow rate temperature in the actual UFH pipes up at about the same rate?

What can be done with the offcuts of PIR board that just can't be used anywhere else in the build? Can it be recycled in any way? If it has to go to the tip, does it count as DIY waste (usually plasterboard, rubble etc...PIR not listed by our council) or does it just go in general waste at the tip or a skip? Would rather not just put in landfill if possible!

This is the thermostatic ERD shower and example of the bath mixer taps we plan to fit.

So on this picture, the green circle is around the pipes where the shower controls will be fitted, the blue circle is around the main feeds (plastic to copper) and the bottom of the shower feeds going back into the wall.

We've had plumbers in to install first fix pipework in our self-build followed by what they called a "mid fix" of plastic to copper pipework to come out of the walls ready for us to close up. In the main bathroom we are having a bath with taps and shower over with separate thermostatic controls (i.e. not a bath shower mixer). The pipework for the bath has the main hot and cold feed pipes going to copper and then a separate C shape of copper pipework going back into the wall and then out again where the shower controls will be. We're wondering why the main feeds couldn't have just had a T off to the bath taps and then continue on up to the shower? Can we adapt it to this? Is an isolating valve on the pipework to the shower required? The feeds come from a manifold with separate isolating valves in the utility room, the cold comes from a balanced feed (if that's the right terminology) and the hot from the hot water cylinder which is ASHP heated. Photos to help illustrate!

We are about to start lining and filling our stud walls and would like some advice on acoustic and normal cavity insulation please. Studs are either 150mm (6x2) or 100mm (4x2) wide, mostly 400mm centres (so the gap to fill is only approx. 350mm wide). Architect specified 50mm Isover APR 1200 insulation, but we're happy to look at similar products such as Rockwool and Knauf. How much of the stud wall depth should you fill? 50mm doesn't seem enough in either 100mm or 150mm stud depth. Do you need to leave an air gap or fill completely? All the products seem to come in 600mm width, with the exception of the Rockwool Flexi at 400mm, but more expensive. Am I missing something on the market that is made for 400mm centre studs or do you just have to cut down and expect wastage? Walls will then by lined with plywood and plasterboard. Thanks very much.

Thanks all for your thoughts and advice, very helpful. I haven't actually seen class I, II or III on any descriptions of ply products!

Thanks, so class I is softwood?

Thanks, I'll check (and find out what that is!)

Ah ok, thank you. I will take a look at the regs. I'm told WBP is an old term, but essentially is the current hardwood that is suitable for exterior use, so some water resistance.

Hello, we've built a timber frame single storey house, watertight and screed poured, so now looking to start lining the walls - internal studwork, internal load bearing walls and the inside of the external walls. The technical spec just lists '9mm ply' or '18mm WBP in the bathrooms about pan, cistern and wash basins' (with vapour barrier under the ply on the external walls, and 12.5mm plasterboard over the ply on all walls). We want to use 12mm ply throughout for extra depth to aid hanging things on the walls, and don't plan to have wall fixed basins etc (will opt for free-standing). I've just rung round the various builders merchants and timber yards and got differing advice on what to use! Is 12mm softwood ply acceptable in all cases except the bathrooms where we could use hardwood instead (for its more waterproof properties)? Thanks

Hi Tony, interested to hear how you got on with installing a mist system and which company you used? Thanks.

Thanks all for your thoughts and suggestions. Having got a clearer idea of the full set up and requirements from the sprinkler companies, I sent an email to our BCO to update and ask for confirmation of likely approval of it all...and to ask one more time if there was any other way to mitigate for the fire access issue. And he has now suggested we could look at mist systems that comply with BS8458, which could be an acceptable alternative, despite me asking about them 2 years ago! So, back to the research drawing board with fingers crossed for a positive outcome!

We'd really like the original company to supply us with all the right info, but after several emails and trying to call them again today, still no further forward. Also tried to arrange a site meeting with them, and not yet got a positive response. Time to ditch and move on, despite deposit paid for initial sprinkler system.

Thank you. My previous research on this suggests that water mist systems don't meet BS9251 and BS9991 which is what we have to comply with. Will check again though.

We asked about a dedicated sprinkler supply when we applied for our water connections and they said they wouldn't agree to it, and that was 32mm! We are fairly rural and the pipes come up a hill from the mains pipe, so I suspect a bigger pipe will still not give us the flow and pressure we need, but will explore again.

Thank you, I've seen this table as part of my research, will look at it again. 3 phase hasn't been mentioned by the various companies were talking to, and not sure we can achieve. We've been told 3000l by one company and 5000l by another!

I just wish it was all a bit more joined up - why give permission for something when building regs then impose restrictions or make life difficult to achieve the permitted scheme.

Unfortunately we have to comply with cat 2 as it's to mitigate for fire access, so need enough for 30mins of water. Didn't know there was a difference on categories until this week, and assumed cat 1 but BCO says cat 2. We also don't have a loft as they are all single storey buildings - they are like barn conversions but now new build replicas, if that makes sense!

So far I've been told that 3000 litres is ok for cat 2 i.e. 100l x 30mins.

Our building control officer has said we need sprinklers to mitigate for fire access for our new build project (it's ridiculous as a fire engine would definitely get here in reality, but on paper our lane isn't wide enough and is unmade), and on a category 2 provision, so 30 minutes run time. We are building three single storey replicas of the pig farm buildings that were previously on the site (long planning battle once conversion couldn't be achieved) which will create two houses, one with a garage which also requires sprinklers. They are all timber frame construction with mostly timber cladding, so we do understand the benefits to having a sprinkler system if the worst should happen, but still feel very forced into having it. Typically our mains water supply doesn't meet the flow and pressure required so we're now looking at a 3000 litre tank and pump. Still working out if it can be underground (but would still need an overground control centre as it would be shared with my brother in law's property) or if it will have to be overground...which causes panic in terms of what it looks like/implications for planning as we are in a conservation area within no class E permitted development. We have been working with a sprinkler company so far but they haven't been great, and as things have got more complicated in terms of the tank etc, we are even less impressed with them. We're already at first fix on our house so need them their first fix in soon, but need to know what the full set up will entail before we fully commit (including pipes and cables in and out of the house), and currently don't feel we want them anywhere near! We have started talking to other companies again, too, but getting conflicting advice about the tank (under or over ground) etc. We would love to hear if anyone else has got a tank and pump for their sprinkler system, what it looks like and sizes, and if you have been able to put the tank underground, or if there is any overground set up and what that looks like, too.

Thank you, we've gone with 900mm.

The approved docs say svps should be ventilated to 900mm above openings when within 3m - does the same apply if there isn't an opening within 3m, and for a single storey building?

We've built a timber frame on block work foundation walls with block and beam floor. All our internal walls are either built on lower block work walls (it is single storey and some of the internal walls are load bearing/supporting) or directly onto the block and beam floor as we don't intend to change the layout. The section and foundation plan drawings show an insulation upstand around the external walls but do you normally also run this around the internal walls of each room as well? Or should we because of the internal walls being directly on block work or B&B floor? Does the upstand also double up as the expansion joint for the screed, or is that something else entirely?! Thanks!

Yes, I'm pretty sure it does.