Replacement Garage Roof

Sew_Late

I’ve got a prefab garage (the type made of panels that slot into grooves in posts and are then bolted together). At the moment it has an asbestos roof, which I’m looking to replace.

Most of the quotes I’ve had so far are for a flat roof with a timber structure, finished with felt. However, one roofing company advised me that a timber/felt construction might be too heavy for a prefab garage. They suggested that over time the extra weight could cause the walls to bow, and recommended a lined metal roof instead, which would be much lighter.  He's shown me pictures of metal roofs and it is quite an attractive look. 

This is the first time I’ve heard that weight might be a problem—none of the other companies raised it. All companies are well recommended. 

So I’d really appreciate any advice:

• Has anyone here had experience replacing a prefab garage roof?

• Has anyone used a metal roof, and if so what do you think of it?

• Is the concern about the weight of a timber/felt roof on a prefab structure valid?

Any thoughts or recommendations would be really helpful.

badmemory

Does your roof have concrete supports going across.  Besides the front & back mine has 3 with one that is where the roof panels overlap.  Just recently some of the concrete has broken off that middle panel exposing the steel? inside.  I am quite worried about it & will be reading along.

Swipe

I'd be inclined to go with the metal roof and can see it outlasting a flat timber and felt roof

https://www.jjroofingsupplies.co.uk/blog/how-long-does-metal-roofing-last/

WIAWSNB

I'd second the box section metal roof as it should be a direct replacement for the asbestos, is light, looks better, and it should easily outlast a felt jobbie. 
And, because it's a much simpler job, it'll likely be cheaper too.
Tbh, I wouldn't expect a ply/felt roof to cause weight issues, unless your garage was actually failing! But, metal is better.
Some folk find condensation forming on the underside, but this shouldn't really happen in a normal garage which tends to be naturally 'ventilated'! I understand you can get 'coated' undersides to help, and hopefully others will comment.
Have you had quotes?