Pergola roof advice

[Niccc]

Hi!

This winter I made a sort of pergola/lean to on the back of my house, it's about 2.5m high, 5m wide, 3m front to back.

I put a white tarp roof on just to get me through this year, and as expected it's sagging and going green with moss etc where the water gathers

I'm going to take it down and replace it with white or clear polycarbonate sheeting

The pergola is sloped from house to garden so water will run off the front ok

It looks like there are trims you can buy for fitting such a roof, and the plan is to have 4 long sheets going from the house towards the garden to fill the 4 gaps between the 5 beams going from house to garden.

My question really is, shown on the crude diagram below with the blue square being the first sheet I will fix, how do I go about fixing subsequent sheets?

I can't see how I can reach across to screw the glazing bar into the beam along the shared join between sheets

The sheets will be about 1m wide so I just can't reach that far, yet I've looked at pictures of pergolas done in this way

Do fitters just climb up onto the pergola for access? mine is made from 100x100mm timbers so it's strong enough, but I fear I'd crack the sheets of plastic

I've only got a set of smallish steps, maybe a much taller ladder would enable me to lean right over?

Any thoughts on this method of roof and how I might fix it gratefully received!

I was thinking just a bead of silicone between the sheet and the house at one end, and the glazing bars along the edges would make it reasonably waterproof?

Cheers!

Nick

Untitled

• Niccc
• 8 Aug 2013
• 1

 

[catengineman]

http://www.polycarbdirect.co.uk/product_desc3_emi.php?id=12
I used this idea and with the use of a 'crawling board' I layed onto the sheeting I managed to snap in the holding strip and also did the lead work at the brick join from the house.

 

[Niccc]

That looks like a great system, thanks a lot for the link

Is the sheeting held in place by the glazing bars snapping together, or do they need screwing down at all?

Did you need to use any sealants or aluminium tape at all? or were the trims and flashing enough?

Does the "self-adhesive" flashing just stick to the brickwork of the house?

I appreciate any answers!

Nick

 

[catengineman]

I did not need any other sealant or adhesives
the lead I used was chased into the brickwork as normal then formed over the top edge of the sheets and frames to make a weather seal

 

[Niccc]

Thanks for the info!

I actually went ahead and bought a snap together system from these guys;

www.nick-gray.co.uk

The guy who runs it replied to my questions and was really helpful, they have a self-adhesive foil strip for the joint between roof and brickwork, I'll let you know how it goes

I never made sure all the joists were exactly the same distance apart when I built it as it's large and unwieldy and was a bit difficult to get up alone, so the distance between joists may be out by an inch or so front to back, so I'm a bit concerned how hard it will be to cut the sheets to fit

Thanks
Nik

 

[catengineman]

A fine toothed jigsaw will go through and you should not have too many chips down the cut, if you have a jigsaw that has a variable speed setting the medium is best or the swarf will amalgamate behind the cutter.