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Fix holes in steel barn roof from the inside?

Q. I have a very tall barn with a steel roof. It has a number of small holes and rather than go up on top (which is a very scary thought) I would much rather try to fix the holes from the inside. Can I plug the holes from the inside?

Dave Snihur
horse enthusiast - London, Ontario, Canada
August 21, 2010


A. You can try. Your degree of success will depend on the size and type of holes and your technique. If the holes are the result of corrosion, your repair will be only temporary, as the corrosion will continue. I'd suggest you try urethane caulk.

Once corrosion to the point of perforation has set in, the only real answer will be a new roof.

jeffrey holmes
Jeffrey Holmes, CEF
Spartanburg, South Carolina


A. The easiest thing to do would be to squirt a small amount of real silicon caulk up thru the hole. A poor fix, but it is cheap-unless you fall.

James Watts
- Navarre, Florida

A. Yes.
Even if you want the patches to be physically on the outside you can repair from the inside.
Cut oval or rectangular holes and feed the larger patches through, short axis to long axis and turn them through 90.
If you apply a sealant to the mating faces you should be able to make a watertight seal.
Blind fasteners (such as pop rivets for metal) would then be used to hold the patch in place through the overlap.
If you can get the fasteners through whilst the sealant is still wet it will help squeeze the sealant down to make the repair watertight and hopefully create a fillet around the patch to reduce the chance of crevice corrosion.

Ciaron Murphy
Aerospace - South Wales, United Kingdom

A. Somewhat old formula is mixture of iron powder(or zinc) and waterglass (thick paste), today you can use 2 parts epoxy cement mixed with iron powder (or zinc powder). Hope it helps and good luck!

Goran Budija
- Cerovski vrh Croatia

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