roof safe for pv install

[ggman]

Hi all
I am currently looking for a possible PV panels installation on my roof size approx m 5.7x5 facing s/w.
My area of concern is the actual roof :the rafters are mm 35x120, The house is located at approx 100m altitude, the wind is always very strong.
Speaking with few builders I was told that i am looking for troubles if I proceed with the installation, due the wind lift on the panels, eventually moving the roof causing leaks and or roof damage.
I am living on RM4 area.
Any comments or suggestions would be highly appreciated.
Many thanks!!
ggman

 

[SpitfireW'sale]

You need to have a structural survey carried out by an appropriately qualified professional if there is any doubt whatsoever. It is best practice to have one done for every install, but many companies don't due to cost.

You shouldn't rely on opinions given about the roof on a public forum, even a good one such as this!

 

[ggman]

I posted this thread cos a company sent by Tesco came to have a look, the young chap was ok got some pics make some measurement, told him about the strong wind problem but not heard anything any more, today I found out that the company is gone to administration, is there any reputable company that can be trusted?

 

[Gavin A]

can't say for sure, but as long as the rafters are accessible it's almost always possible to improve the structural strength sufficiently relatively simply via the use of noggins, doubled up rafters, additional diagonal bracing etc - as any good builder ought to realise.

They'd probably be right that it wouldn't be good to just bang the panels on the roof as is though.

 

[Worcester]

Should also need to consider the total uplift so that it doesn't lift the whole lot up, so some tie downs may be needed.

Tiles (and panels) get sucked off roofs not blown off.

Get a good structural engineers report first.

 

[The Solar King]

All depends on construction of roof. If these are engineered roof trusses, in a relatively modern house, all well and good. They will be strong and designed with a high level of redundancy in them. If this is an older property, definitely needs a structural engineer involved. We did a system built post war property where the roof was hardly strong enough to support its own weight. Ended up doubling up purlins and fitting plenty of tie straps. Work is indemnified by the Engineer, that's why you employ one if there is any doubt what so ever.

 

[garyson02]

My suggestion is, you should consult with good expert regarding this issues.

 

[dansk]

All depends on construction of roof. If these are engineered roof trusses, in a relatively modern house, all well and good. They will be strong and designed with a high level of redundancy in them. /QUOTE]

Interesting comment regarding trusses - the last truss roof we did failed the structual survey because they are design to inch of there life to keep costs down.

 

[The Solar King]

We have worked through several with our structural engineer including his own house. There have never been any problem with either dead load or or wind uplift on the structure itself when panels are attached. Design of trusses should account for the fact owners will floor the attic space and load it up with junk.

 

[dansk]

Suppose different areas of the land i guess - i had this out with them at the time, but they where adamant and therefore i have to trust their judgment.