Thanks for all the responses, I’ll try to ‘cover’ all queries/advice here….
The roof construction is somewhat as expected in that it’s a combination of trusses (the majority) with some cut rafters - everything at 600 centres.
Based on the minimum lap specified for the tiles (75mm) the gauge should have been 325mm but, as intimated earlier, a CONSIDERABLE number of the tiles showed a gauge of around 350/360mm (ie 50/40mm lap) and so we have (obviously) completely removed and replaced with the correct gauge which has resulted in an extra course on each of the slopes worked on.
I do find it hard to believe that someone would even attempt such a roof without understanding how to work out a gauge etc…..we’ve debated this to death and considered whether or not he…..ran out of money and tried to save tiles (eg given no overhang on SOME initial courses); bought a job lot of ‘seconds’? (a considerable number of nibs were missing); didn’t pay/fell out with his roofer (if he didn’t do it himself) who then cut corners; inadvertently built the house slightly out of square - this is an interesting one because there is some evidence of ‘creep’ which I would describe as the strange phenomenon between adjacent slopes where the distance between fascia and ridge should be exactly the same and at the same pitch, but are apparently not - it then could be that he started on the one slope (the largest as it happens) that has the correct gauge and subsequently worked his way around the house on adjacent slopes BUT trying to maintain the same batten positions instead of rechecking the gauge calculation…..this would then offer some kind of answer as to why the gauge appears to be getting worse by the time he got to the rear slopes?……still doesn’t forgive other basic setting out issues however.
I do (and did) take the point about checking the slopes that we’re not going to work on and ultimately gave my mate all of the info he needed to make the ultimate decision…..don’t get me wrong, if there was anything even remotely causing an issue I wouldn’t have let him say ‘no’ to redoing those slopes. However, based on his historic observations and the obvious water leaks suffered over the years we‘ve identified (as far as I’m concerned) all of the reasons for those problems and, as I say, he‘s now well armed to make the reasoned choice….in fact we laughed the other day as he was commenting on just how much he’s picked up and read about since I’ve been sending him web links etc…..I said “that’ll come in handy after we’ve left and the rain floods in - you can sort it out yourself”
….made me laugh anyway!……Based on the above we ARE going to leave a number of slopes as they are knowing that there gauge is wrong because there are no penetrating issues whatsoever, they are also more sheltered.
Now, here’s another potential can of worms that I wasn’t even going to mention……..the house has a lovely bathroom plus an additional small wc/whb room within the double garage which is extremely handy for use by anyone with dirty garden boots or anyone (like us) working on the house (tradesmen’s entrance etc) but…….WAIT FOR IT……on the first day he says to me “we don’t do number two’s in there”, “why not” I enquired, “well“ he says “the drainage from that room runs to a soakaway”
Both myself and my other mate (an older very experienced tradesman) laughed that off by saying, something like “impossible”, “no chance”, “wouldn’t have got away with it” etc etc but he’s adamant that the prev owner told him that they added it after the house had been finished, certified etc and so no one would ever know and so (in the prev owner’s words) “just for info, we only ever pee in there so be careful”…….you couldn’t write it!!!!
Anyway, I’m going to have a look at it when we’ve finished the roof as they’ve already been using it (for number ones) for years and I’ve got my hands somewhat full with the roof at the mo
I‘m painting a very dismal picture of my mate here but it’s made me realise that even ‘seemingly’ bright people (he’s a consultant manager - not anywhere near construction btw) don’t necessarily understand how things, whose workings I take for granted, are supposed to be put together and supposed to function.
On a final note - this is the first time I’ve actually sat back to consider the ultimate repercussions of what a simple line (drawn by an architect) actually results in with regard to the guy at the sharp end when building the house. I’ve long given up now but for years used to do drawings for planning/building regs and although I didn’t need to produce any architectural award-winning designs (mine were mostly extensions) it has made me rethink this process. We had this same discussion when working on the the rear slopes of the house where the rear cavity wall could have been made longer instead of including the small return which resulted in the roof requiring another ‘return’ slope with a width of no more than 1200mm but possessing a hip at one side and a valley at the other……all bloody cuts!!!!!!! I’ll have nightmares about these till I die.
