RichS

@recoveringacademic, did you ever go on the training day in Barnsley, and if so was it worth a day??

On the volume part, I'm intending using one of the companies that actually mixes "on site". Apparently the wagon can carry enough materials to mix up to approx 10m³, I can't imagine one pour would require more. Using this method you never get left with excess concrete to dispose of and you only buy what you use.

Yes, leave a gap at the bottom, even if only about 20mm, to be hidden behind the skirting board. If any liquids get spilled on the floor this will prevent the damp from rising up the boards.

Thanks Nick, wondered how people did that Thanks Nick, wondered how people did that

Yes, obviously after you have leaded the valleys.

Going by other threads on VAT I would GUESS it's a no as it does not form part of the fabric of the building, but no doubt I'll be wrong

If you go the LPG route try Flogas as opposed to Calor. Far more competitive on price in my experience and the supplier I am currently using (though nothing to do with my house).

I'm afraid I don't know of any better seals than what are normally available but I do agree with you 100%. This has always been an irritant to me, ok, it's only a garage, but surely a warmer garage is better, especially if you work in it a lot.

Jamie, If you already have a 1/40 fall why do you need firrings??

I have a balcony planned into my build. Mine is over part of the garage so obviously must be watertight. I intended to create the fall using firings on top of the joists to an outlet in the corner. 18mm OSB3 decking and then fibreglass covering. My thoughts for the balustrade, also glass, was to fit some male dowels to the decking/joists before the fibreglass and then slot the female balustrade posts over these at a later date. As for the finish surface I was thinking of tiles or similar.

Hi Vijay, Thanks for the answer. Must admit I never gave clay a thought and now it makes sense. Very sandy where I am so water just disappears

OK, now I know I'm on the correct tack I will ask this question of Vijay, and the answer may be simple but I'm just too thick to see it. What would be the reason to use a non permeable membrane under MOT1, surely this will just hold water. I would have thought you would need a permeable membrane to contain the MOT1 but let liquids pass through. Edit Just had a thought. is it to stop water from rising into the MOT1 and not the way my mind is working???

Oh good, thought I was losing the plot

Have I got this wrong??. I thought non permeable didn't allow water (and others) to pass through, so surely water would pool on it.

As above, with a cut roof and 50 x 125 rafters I would use a 25 x 200 ridge board. As Nick explained better than me the ridge in this situation is not structural. The roof gets it's strength from the triangulation of rafters / ceiling joists etc all being nailed together. This stops any spread loading on the wall plates (even though it's only a dormer).

A ridge beam is a structural element to the roof that carries and spreads the loading on the rafters. Am I correct in thinking that you are doing a "cut roof" and not using trusses or have I got the wrong end of the stick (again)

I'm assuming you mean the ridge board as opposed to a ridge beam. If it's only a ridge board 50 x 250 is way overkill, with 50 x 125 rafters I would use more like 25 x 200.

Ha ha, not a problem. Just as an aside, I don't know what you're cladding the dormer cheeks with (lead or tile hung or other) but if you simply nail another piece of timber to your outside spar you will have something to nail the main roof tile lath into where it butts up against the dormer. Yes it will carry without but it's a better job with.

No, you will have to build the dormer cheeks on the same line as the spars otherwise you will have a step on the inside. The stoothing for the cheeks will sit on both spars anyhow because of the width, even if only using 50 x 75 which would be the absolute minimum.

1, Obviously you need the clear space for the width of the dormer cheeks and then add the second spar on the outside of that. 2, I'd bolt them about every 600mm

Yes, I think that would be best as the only other place for the manifold would be in the utility and that is not very central.

Thanks for the speedy responses. I will try to attach the floor plans to give some idea of the layout. The boiler, which is now decided as a Vaillant combi will go in the utility and I reckon I can get the ufh pipework up into the cylinder cupboard via the kitchen/utility wall without it being seen. Ground floor.pdf First floor.pdf

Oops!!! Must start wearing my glasses when I'm reading Sorry about that.

Is there any free software available that will design the layout of underfloor heating pipework, and if not what is the alternative. Like a number of others on the site I have found it hard to decide on whether first floor heating will be required. I have now come to the conclusion that at least the master bedroom, which sits directly above a 45m sq unheated garage, will probably need some along with the en-suite and bathroom. On the advice I have seen from Nick I realise that the manifold would therefore have to be on the first floor, but trying to work out the pipe runs seems to be a bit of a nightmare. Any ideas ??

I'm surprised they can make those for £135.00 so I'd rip their hands off.