observations and another question

[yorkshire1]

I have noticed more and more roofs are counter battened nowadays, and was just wondering why this is, as i only remember counter lathing when laying old grey (york stone) so the alloy pegs never went through the felt.
The only reasons I can think of is:- 1 type of fixing 2 some form of breathing space?
My other question is regards to the hip mitre, what is the formula as to the measurements to make the cuts on the ridge, when I was a lad 8" and 2" and 2" and 2" or was it 7" and 3".
One last question is it possible to get any up to date theory and practice literature i.e. books, CITB, or course paper work any of you lads may have?
Cheers in advance.

 

[noseall]

the increase in counter batten use is largely due to the demand for more space. loft space is now being used as habitable dwelling therefore the insulation needs to be placed either between or over the rafters.

either way, counter battening of the roof is now a requirement in order to deal with the insulation and venting.

regards the hip. are you referring to the tile cuts?

 

[corrie]

I think Yorkshire you are refering to cutting the hip tiles in a repeating sequence? 8" at bottom and 2" at top?Join up the line and cut?I usually make a few templates from slates if it`s Rosemary....... or Mineral felt if it`s Ludlow or similar. With a good Stihlsaw it not such a big deal as when we used to cut Rosemary by nibbling them over a steel...........or cutting the Ludlow with a Lathing Hammer.

Good tech books come up now and again on Ebay but they aint cheap.

The counterbatten thing does aid ventilation. In Scotland we have always had sarking or sheets across truss....then felt and tile batten (sarking and felt only on slates or Rosemary) On these roofs of 50 yrs old with tile batten and board without C/B you notice that any condensation or rain driven under tile gets trapped against top edge of batten...........making it soft or even worse. When counterbatten started getting specified 30 plus years ago one of it`s functions was to let water out that may get in through any number of reasons. The gap gave any water a free passage down into gutter where felt had been led into.

Alex

 

[yorkshire1]

I see, I think! Counter lathing is basically so the insulation used is not touching the back of the felt/membrane and in turn stopping the felt/membrane touching the back of the gauged lathes, therefore rain can not pool or hold behind the lathes which lets the rain run freely to the eave and into the gutter.
As for the hip/ridge tree mitre Im not sure if I explained it properly. The 2 hips you bed and run up to the ridge tree minus the last one on each hip, then you would basically want to start to ridge across the tree/apex, what I am after is the method/formula to cut the 3 meeting ridge with a stihl saw, I cant remember exactly but the cuts on the hip side of the roof were either 8 or 7" to the centre of the ridge and the main roof side was 2 or 3" then you'd scribe and cut, the ridge tree ridge tile was then cut 2 or 3" on either side which when all bedded you would have a neat equal joint throughout all your ridge tiles and no kicking up or stooping down of the last 2 hip ridge tiles, hope its a bit clearer
As for the tech books I will keep my eye out as for Ebay a lot of the books and cd,s are for USA roofers.
Cheers once again.

 

[corrie]

Gotcha Yorkshire ........the Saddle we call it. American roofers use a lot of Felt shingles don`t they? Mmmm quite good for Wendy houses

Alex

 

[datarebal]

it will differ with roof pitch

 

[yorkshire1]

I understand that data but am I thinking along the correct lines with the measurements albeit in inches?
Cheers fella