What is the name of this screw on top of garage roof that is causing a leak?

united4ever

and are they easy to replace? somehow it is not flush with the roof and is letting in water - the other ones are fine. Been there for 8 years with no problems until now.

stuart45

Roofing screws are easy to install. Take it out and check the rubber. It may need a new screw, or possibly just tightening up. 

united4ever

how do you take them out? Is twisting with a pair of plyers any good I don't have much except the usual screwdrivers.

stuart45

Ideally you need the correct size socket. It might come out with pliers, but you need to get it back in properly. They should really be screwed in at the correct torque, and under, or over tightening can cause problems.

Section62

united4ever said:

and are they easy to replace? somehow it is not flush with the roof and is letting in water - the other ones are fine.

The screw is covered with a plastic cap, possibly not pushed down as far as it should be - you should be able to carefully pull that off with your fingers.

Underneath there will be a metal screw with a hex head, and as stuart45 says, there will be a metal and EPDM washer.  The EPDM washer is the part that creates the seal against the roofing sheet.

If tightening up doesn't work you may be able to get a replacement washer, but you need the right size for the screw, and you may have to hunt round for smaller quantities (than 100)

E.g. https://www.screwfix.com/p/easyfix-carbon-steel-nylon-epdm-washers-m7-x-3mm-100-pack/7852h

If the screw is faulty then you'll need to get the right type of replacement - they are available as metal-wood and metal-metal. It depends whether the sheets are fitted to wood or metal purlins/supports.

A common problem is the screw being overtightened and 'pulling' out of what the sheets are being attached to. If that happens the screw won't be tight enough to form a good seal.  If that's the case here then you'll need a larger (diameter or length) screw, or else find a cunning way to get the screw to tighten (aka bodge it). 

Obviously you have to reuse the hole in the sheet rather drilling a new one...

Eldi_Dos

A set of box spanners is a handy thing to have in your toolkit, may be not robust enough for professional use but handy for occasional use.

FreeBear

Section62 said: A common problem is the screw being overtightened and 'pulling' out of what the sheets are being attached to. If that happens the screw won't be tight enough to form a good seal.  If that's the case here then you'll need a larger (diameter or length) screw, or else find a cunning way to get the screw to tighten (aka bodge it).

If it is screwing into timber, cut a thin peg out of wood, smear a bit of glue on it, and tap in to the hole. Make sure the peg is tapped in below the level of the roof sheets, then screw in a new bolt - The wooden peg doesn't need to be a tight fit in the hole.

If the roof truss is steel, then a nut & bolt may be a better solution than a self tapping screw. Would need the assistance of a little helper inside with a spanner to stop the nut from spinning when doing the bolt up from above.

A little blob of mastic or silicone sealant under the head of the screw will make sure it doesn't leak again.

stuart45

If you can borrow an adjustable spanner it would help. Probably best to remove it first and clean underneath the washer and roof. When you tighten it up don't over do it and give it a water test with the hose. Tighten up more if needed.

JohnnyB70

united4ever said:

how do you take them out? Is twisting with a pair of plyers any good I don't have much except the usual screwdrivers.

No, either use the right size socket / spanner, or get an adjustable spanner and use that.

Risteard

It's a Tek screw.

united4ever

Thanks, yes, the roof truss is streel. Will have a go after work but took off the rubber cover and tried gently tightening the rusty screw with some pliers - it was still spinning with the washer (as mentioned, maybe need someone inside to stop the nut spinning) . Don't have a hex screw head that size or spanners.

The rubber cover is cracked too so maybe that also needs replacing.