G and J

It also looks the part!

Ok just in case it's of interest......we met with our architects last week to finalise detail as we move into BRegs and Discharge of conditions. Long story, but we have added block skin to back render on ground floor and it's our preference that the upper storey cladding overhangs the ground floor render........question was "can we effectively extend the cladding into the airspace beyond our planning footprint" - we were talking 31mm on each elevation. Now caveat to our situation is that we are on a narrow site (1m from a "very intetested" neighbour), but our architects view (local, working relationship with LPA) was that pre covid, he may have seen one enforcement action a year, he currently has 8 on the go, with a number of those needing to go back into planning.......his advice was "do we want the added hassle?"

I think that’s exactly what we are facing. We’ve a 3m x 5m flat roof with a fair bit of that taken up with a skylight. I think the difference between internal ceiling height and the top of the parapet that surrounds the flat roof is between 450mm and 500mm. Posi joists will be 254mm, plus we need to be able to walk on the flat roof for maintenance/window cleaning. Reading this thread it sounds like we’ve no choice but to have a cold roof, but how on earth do you ventilate it?

Snap. Only I’m too tight to buy PHPP so I used Jeremy’s spreadsheet.

We are planning to have rendered blockwork on the ground floor with vertical wood cladding upstairs (assuming we get our non material amendment approved). The step issue was the same for us so are planning to step out the upstairs frame in places rather than build in voids. @CaptainRatty Could you do that or is it too late?

Would I be correct in inferring that the main benefit from a pressurised system comes from the quality of the tank? If so I could use a pressurised tank but on gravity. 🙂

Good plan. I assumed I would have to screw the frame straight to the timber. Ta for that.

Like this you mean?

My understanding is that they aren’t big enough, they’re only about 2’ either side, hence steel being unavoidable. If the goalposts are in the corners, then methinks, I can thicken up the timber frame between the post and the patio door and reduce the effect of the cold bridging?

On the back of our house we will have a 3m single storey bit with a flat roof. The rear face of this comprises a 4.1m set of patio doors flanked by two little stubs of wall. We've been advised that we need some ‘goalpost’ style steel to provide racking strength, which I can easily understand. What I can’t work out is if it is better for this steel to be tight to the patio doors, or is it better to have it full width, i.e. into the corners. I can imagine that option 2 is better from a cold bridging point of view but I can also imagine that I’m missing some other fundamental factors. Comments appreciated.

Crumbs, the things I don’t know! Thank you.

Is it ok to use beam and block outside? I thought the metal reinforcement in the beams might blow?

Cash is not profit.

Whoo hoo!

My close knit family of 18v Makita batteries means that I’d never think about anything else. The instant start stop, the lack of fumes, lack of noise do make it so much easier. We won’t need a brushcutter at the new pad (we declared war on ongoing maintenance requirements) otherwise I’d have already gone twin 18v. As for using non Makita batteries…. :-0

Crumbs, funny how different things can seem when a more interesting and illuminating viewpoint is highlighted. You should consider doing this for a living @Gus Potter 🙂 I think of concrete as totally inflexible and solid, but nothing really is. If I think about two people standing on a thin sheet of ply on a lawn, no one would be surprised at it bending if they stood right on the edge. But if they moved in a bit it would bend less. Shock! The more I think about this the more I like strip foundations.

Husky chainsaws and Stihl kombi brush/hedge cutter for years. In my garage I had lots of 18v makita drills/routers/saws/etc. Decided to try battery based hedge trimmer. So impressed. All electric now, apart from the Stihl stuff I’ve not yet got round to selling. Will never go back to petrol. If you’re going to be using the brushcutter for a few years I’d strongly advocate making your life easy and going electric (and I’m with onoff, makita stuff is fab).

Re: Cladding - dunno, might be, certainly the concern about cladding in general won’t help. Might be more about the British obsession with masonry, which I have been guilty of in previous years. Re: Mortgages - dunno that either. Underwriters aren’t ones to share their thinking, and they focus generally on volume and risk. So if their criteria accidentally disqualifies the most fabulous builds which only constitute 0.17% of the market why would they worry. I was recently surprised to hear of a Hanley self build mortgage which gives slightly better terms but is only applicable if you are at wall plate. My guess is that that is because most self builds that fail do so before wall plate.

We’ve been looking at mortgages, including self build, standard and lifetime. First thing we noticed is that some self build mortgage lenders aren’t so keen on lending if you already own the site. Second thing we noticed was that some mortgage companies inc. self build mortgages are particular about the type of build. Hence we are now looking at reducing the amount of wood cladding to less than 50% and we are putting in a blockwork outer skin for just over 50% of the external walls. We’ve had useful guidance from a specialist broker, so don’t be afraid to talk to one of those.

OK, J just found out what perpends are and now I understand your point @ADLIan . So maybe the TF200 Thermo will help a bit. I’m minded to derate the insulative contribution by a third….

PS. Julia is wondering it’s taking you longer answer all my stupid questions @JohnMo than it would to build our blooming house! (I do appreciate the help though guys).

This is (an attempt at depicting) the issue that’s on my mind. The expansion and contraction of the frame due to varying temperature and moisture level won’t be matched by the thermal expansion and contraction of the PIR. So the frame shrinks, the PIR pushes on the plasterboard and the screw digs in a bit. Then in winter the frame expands and the PIR doesn’t and the plasterboard suddenly has a small gap behind it and pop!

Noted, ta.

Understood re nails. Re the air gap question, I’ll draw it out.

So with screws need I worry about maintaining an air gap behind the plasterboard?