We are building a multipurpose workshop/shed on my mum's smallholding.
We had never built anything bigger than a 3m x 2.5m garden shed before & done some d.i.y. that gave us delusions of competence!
So it has been a steep motherfucker of a learning curve….
Anyway I have some technical probs with the doors, windows and the z- purlins on the metal roof and I was hoping that anyone who works in construction might have some advice or thoughts about the following Q’s.
None of our mates are in the rights trades or professions for advice and the ones that have done building work say ‘yous know more than me now’. 
We learnt out of books and the internet and asked for advice a lot. We have photos here http://www.flickr.com/photos/scotspinehedge/sets/ that kinda explain the questions.
1) Leaking around doors and windows. The windows sit in rough openings that we made a wee bit too big. So the gap around them can be anything from 10mm to 40mm (40mm at the top not the sides). We were gonna put in this tarry kind of flashing strips (bendy, cut w a stanley knife, metallic coating on one side) but we had help putting in the windows and doors cos it was too complicated for us. So we paid and worked alongside this really nice guy who’s a carpenter/joiner with him as gaffer (.. so relaxing for someone else to be in charge for a bit) - and he gave us some advice. He said not to use the flashing strips which we had been going to put round all the door/window rough openings over the breather membrane that folds in and over them. So we didn’t and just left it. He said fill in the gaps with expanding foam. Most of them don’t have the foam in yet.
But now they are leaking and this other dude said fill in with sealant but the gaps are too big for that I think. He said expanding foam can leave critical holes which will allow water penetration. Also got a cheaper sealant (no nonsense) which I was prob a false economy as it seems to soften and go squidgy in the rain even alto its supposed to be exterior grade. And with the doors they are leaking under the extra framing the carpenter put in the rough opening to frame them i.e. in between the new framing and the original rough opening with the housewrap on it.
2) water being redirected onto the wooden cladding instead of into the guttering at 2 points. The roof is a composite metal roof i.e. it has insulation integrated into it, sandwiched in between 2 sheets of metal. It is set on a simple shed roof (single) slant. So at the lower end the water runs of into the guttering. But when the roof was first put on it turned out the company had missed out two of the metal z- purlins. (They are like z shapes if you look at these pieces end on). So we only paid for help with 2 things during the whole project so far: the doors and windows and putting the metal sheeting onto the wooden roofing we had built. So 2 guys (who were quite nice but had a dog that menaced and bit our dog!) attached it all, did a good job but couldn’t put on final 2 z –purlins cos they were missing. So later I put them on with a friend and now I wonder did I get it not tight enough somehow. I think the pictures explain better than words anyway.
Any advice or thoughts on these dilemmas would be totally appreciated but its fine if you don’t have time… I’m posting this on some other building forums and a kind guy at the sawmill said he would drive out and look at it if we stayed stuck..cheers, dohball x
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