Glass / Tile Roof Valley - Does my Builder have a point ?

[mmw109]

Hi,

We're getting a rear extension done on our house. It is in a T - Shape so that a pitched tile roof runs right along the back of the house (like a leant-to) and then a conservatory glass roof should protrude from the middle (in a T shape) at a 90 degree angle to the pitched tile roof.

This was all drawn and agreed, but now the project has started the builder says that he'd prefer we did tiled roof to start off with on the protruding section as well so that the valleys had tiles both sides, and he didn't have to join glass to tiling on a valley. He says he's worried about leaks or he "sees nothing but problems"

Does this make sense or is he just trying to save a bit of money ? We think we'd much rather have the join on the valley (in a V shape) as it gives us more glass/light/sky and will seem more natural.

If it is the case that this kind of roof is problematic are there any suggestions to help ?

thanks.

 

[Xenon]

Insert lead valley, drop glass on one side and tile the other. Glass on foam strip though.

 

[Nige F]

As per Xenon but the " drawing" you have - is it a detailed working drawing , or an architects one with " detail left to builder " - I`ve seen a few of those . It sounds like it needs a leadwork specialist and liasing with the conny. roof manufacturer. The devil is in the detail on this one

 

[mmw109]

The architects drawing makes it quite clear that its glass to the valley. Ill see if we can talk to the builders conservatory supplier.

Why does the glass need to be on foam ? Wont it be on a frame ?

 

[Xenon]

The architects drawing makes it quite clear that its glass to the valley. Ill see if we can talk to the builders conservatory supplier.

Why does the glass need to be on foam ? Wont it be on a frame ?

Yes, with a foam bedding bar.

 

[freddiemercurystwin]

Your builder is an amateur. Alarm bells should be ringing.

 

[mmw109]

Alarm bells may be ringing, but it's too late now.

Having originally conceded that it's ok , now on discussion with his "glass roof" supplier, the builder is now trying to go back to his idea of tiling round the valley.

The builder is still quite convinced that it is difficult and whatever he thinks he's going to do could leak.

Can anyone PLEASE help me with some sort of drawing or example that I can provide him (and his glass roof supplier) with that demonstrates it is workable.

Thanks.

 

[freddiemercurystwin]

Just get your architect to do a detail!

 

[mmw109]

My architect is unfortuntealy difficult to get hold of.

Can I at least confirm what he should be doing ?


Normal Valley (Lead or GRP). Then with Glass Frame resting on the lead with overlap (so it drips into the valley) ?

Is this "Foam Bedding" inside the Glass Frame (so between the sealed unit and the frame) or between the frame and the leading ?

 

[Alastairreid]

The foam filler goes between the glass and lead.

 

[mmw109]

So do you just mean like a spray foam/filler ? to bond it ?

I was thinking you meant like a piece of polystyrene (which would obviously let water through).

 

[Alastairreid]

Closed cell the same idea as the strips up the side of velux windows,

The weight of the glass compresses it to create a seal against the elements.

A bit like these.

http://www.alibaba.com/product-gs/540311766/polyurethane_foam_strip.html

 

[mmw109]

So the glass roof frame is effctively "floating" on the foam ? Is it just secured at the bottom and top ?

Would there be flashing across the top ?

 

[noseall]

Get the twonk who drew such an awkward junction to actually design the connection and make it so that it works and can be built.

This is not in any text books or building manuals.
Effing stupid design.

It would make more sense for the jut out or the change in elevation to be entirely in tiles, valley and all, then stopping at a gable. The glazed area could then be successfully connected to the gable abutment.

 

[cotswoldbuilders]

It would make more sense for the jut out or the change in elevation to be entirely in tiles, valley and all, then stopping at a gable. The glazed area could then be successfully connected to the gable abutment.

That's what their builder suggested, and I agree it would be a far better job.