Making a removeable fibreglass cap in lieu of flashing

I am building a lean-to conservatory and have a slightly unusual setup. Due to getting a good price on one, but it being too small, I am using a flat roof (draining to the side) between the conservatory and the house

- this also gives a useful escape route and a working platform for house maintenance.

Due to various constraints, I have needed to keep the overall height down, therefore rather than using firrings on top of the timbers, I have the "flat" section of the roof between the joists. This means that the conservatory butts up to a horizontal timber joist, with no height difference.

My intention is to fibreglass the flat roof, particularly as I fibreglassed the flat roof of the existing extension around fifteen years ago and it's still fine.

I am still deciding how to waterproof the joint between the conservatory and the joist and have considered making a fibreglass cap running a short distance over the roof of the conservatory, over the joist and a few inches vertically down the other side. My intention is that this should not be a permanent part of the roof, but instead should be removeable, so as to allow the glazing bar caps and roof sheets to be removed if required.

The obvious way to make this is to put something on the roof that will allow the fibreglass to be released, make the cap in situ and then remove it to place a self-adhesive sealing strip or similar under it. the question is, what to use as the release medium?

Tinfoil would work, but is eaily torn during working and will not adhere to the roof to keep it in place while I work; clingfilm will self-adhere but may shrink and tear under the heat of the fibreglass curing.

Any comments, experiences or suggestions appreciated.

SteveW

Reply to
Steve Walker
Loading thread data ...

Polythene's a good multipurpose release agent. It comes off clearly, dry, and creates a smooth surface. I don't think it matters what happens to it once the resin's curing.

NT

Reply to
Tabby

It's one of those things that makes perfect sense when you know what it's about, hence making it difficult to judge whether it makes sense to anyone else!

I should have said wallplate rather than joist for the one affixed to the house.

I'll try a quick bit of ASCII art, but you'll need to view it monospaced.

This is a view from the end of the conservatory.

CCCCCCCCCJJ W CCCCCCCCC JJFFFFFFFFFFFFFFFFFW CCCCCCCC JJ W

C = the sloped roof of the lean-to conservatory. J = the end of the wooden joist. F = the surface of the flat roof (this slants from almost the top of the joist and wallplate (back of your screen) down towards the middle height of them as it comes out of the screen towards you. W = the wallplate attached to the back of the house.

Below the joist, wallplate and end of the flat roof is a brick wall, sticking out 780mm perpendicular to the house wall.

The top of the joist, down its right side, across the flat section and up the wallplate and onto the house wall are to be fibreglassed.

My intention is then to produce a cap 5.2m long, overlapping the top edge of the conservatory roof six inches or so, over the joist and a few inches down the right side of the joist.

I hope that makes it clearer.

SteveW

Reply to
Steve Walker

You should just be able to see it without doing anything, it's just plain text, but if your newsreader is set to a proportional font, spaces and different characters will have different widths and so things won't line up, using a monospaced font corrects this as everything has the same width.

No, that's no good. I need and 6" section, another 6" section at 10 degrees to that and then a two inch section at 90 degrees to that. In addtion to that the 5.2m length has a 2-1/2" wide (1" at the top),

2-1/2" high trapezium profiled glazing bar ever 900 or so mm.

I do not want to use self-adhesive flashing - it doesn't last long - hence thinking of a rigid, fibreglass cap, made in-situ. However, replacement of a damaged roof sheet requires lifing the capping of the glazing bars upward, hence I can't just continue the fibreglass of the flat roof over them.

SteveW

Reply to
Steve Walker

I'll give a piece a try. Thanks.

SteveW

Reply to
Steve Walker

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.