Box section roof leaking through screw holes

[MrsDistracted]

Hi,

I have a garage built in 1982 with a box section roof metal. During the last winter, it started to leak. On inspection, the caps and grommets on all the screws are perished and some are missing, look like they've been patched before with silicone.

My first thought was take out the old screws and replace, but I guess some or all might be rusted in. So I'm thinking drilling out the damaged ones and replacing with larger ones with new grommets and caps.

Has anyone done this and if so do you have any suggestions for a diy mum, anything I need to know before I start? The roof's easy enough to work on, slight pitch, not very high etc.

Thanks in advance.

 

[Burnerman]

I think you'll have real problems drilling out the old screws-they are made from hardened steel.
Even if you replace with new screws adjacent, the old ones will still leak.
Have you considered a product called Acrypol.....it's a brush on heavy solution that actually works quite well.
A photo could help us here, both external and internal if you can.
John

 

[terrypin]

I'd be tempted to seal(as per previous post)with something like an aquaseal product, something with fibres in.

Messing about trying to remove old fasteners/fixings may cause more problems than it solves. IMHO.

 

[MrsDistracted]

Thanks for quick response. Camera charging at the moment, so no pics yet.

I'd thought of putting bitumen paint on each screw, and thought it would look a mess. Painting a complete layer over the whole roof would look a lot neater. And beats drilling out 100 screws.

Cheers

 

[MrsDistracted]

Thank you!

I ordered 120 replacement screws and set to work taking out the old ones. To my surprise all but a dozen came out easily. The remainder were so rusted up that the screwdriver couldn't grip, and half of them came out easily by gripping with pliers and turning. The last six took a lot of patience with a mole grip, but all done. So glad I knew not to try drilling them.

The weather was so dry until last night, but then that was a proper downpour, bucketfuls of water. Before I replaced the screws, if I went into the garage after a storm, I could hear the roof dripping all over. Today - not a peep.

 

[Burnerman]

Just the jobby!
What were the screws fastened in to - timber?
John

 

[terrypin]

Great result, do you want a job?