Fibreglass Roof and a parapet wall flashing

briaineo

Hi

I cannot seem to find out online how to connect a fibreglass roof to a new build with a parapet wall; existing walls seem to be explained. And I presume there would be a slight difference.

This is what I was thinking: insert a 500mm wide sheet of aluminium flashing into the wall and build a couple of courses over this; and attach the fibreglass Matt to this.

Does the above sound right or am I going about this the wrong way?

Thanks

Eoin

Bonzo Delaney

You may stick up a pic or a drawing or more info with measurements
Is the fibreglass roof higher than the roof it's joining to ?
If it is either rise the parapet wall up 9 inches over the new roof flash cap and render as normal
Or else stud& sheet down to the parapet and fiberglass that surface. With attention to detail where it meets the parapet.

briaineo

Bonzo Delaney wrote: »

You may stick up a pic or a drawing or more info with measurements
Is the fibreglass roof higher than the roof it's joining to ?
If it is either rise the parapet wall up 9 inches over the new roof flash cap and render as normal
Or else stud& sheet down to the parapet and fiberglass that surface. With attention to detail where it meets the parapet.

Hi Bonzo

I tried to post a pic but the mods say No since I'm a new user although I've been a member since 2006!

Basically the parapet wall finishes approx 1 metre above the level of the roof, and the roof is to be circa 220m2.

I was wondering since I'm building from scratch: I presume I should place some sort of flashing into the wall at the same level that the roof it at?

The reason I mentioned 500mm aluminium in the first post was that it came in significantly cheap than lead. Since The linear length of the perimiter walls is 65m.

Thanks

Eoin

Bonzo Delaney

Still can't get my head around exactly what your saying but if you were planing on building a few courses of block above the wall a few roils of 21 inch dpc would be cheaper than any metal.

briaineo

Hi Bonzo

That's pretty much it want to create a deck area on the roof with walls as a railings all round.

I thought I would have to use something more substantial to "bond" the fiberglass matting to.

Would you recommend putting another layer of DPC lower down as well?

Or just the one layer spreading across the full cavity and joining the roof to it?

Do you think I should allow an over lap on both sides with the DPC or just the side the fiberglass is matted to?

thanks for all the help

Eoin

Bonzo Delaney

I was imagining something different I think.

If its a new build
The fiber glass would be turned up the wall about 4-6 inches this is achieved by using a special preformed fibreglass trim fixed to the deck and glassed with the mat when coating
But you'll have to achieve this detail in the block work
https://www.google.ie/search?q=flat+roof+wall+abutment&client=safari&hl=en&prmd=ivsn&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjAyvL8-OPJAhXFFw8KHfKcCkIQ_AUICCgB#imgrc=tZhe_ReE9xoK-M%3A