Roofing patch q

goodcleanfun, Apr 14, 1:03am
I am looking to remove a chimney. Pretty straightforward however nervous about patching the whole in the corrugated iron roof.

Anyone out there have experience in these matters? Is it pretty straightforward? Anyone care to give me a quick run down of what's required?

Thanks.
golfdiver, Apr 14, 2:22am
Assuming it is a brick or solid chimney? Are you removing the entire chimney to the ground? If just below the roof line, are you bracing it on all four sides for Earthquake protection?. If there is a purlin needed it will need to go at least to the next rafter on each side. I've done dozens of them, and it isn't difficult. If the chimney is solid, it can be hard work as you will need a 9 inch diamond blade to cut through the concrete and reinforcing but the block chimneys just lift off in sections. Be very careful dropping it off the side of the house.
echoriath, Apr 14, 2:47am
How old is the chimney?
How high above the roof does it extend?
What pitch (approximately) is the roof?
If it is brick and mortar, how hard is the mortar?
Is the roof open ir is it a skillion roof?
Are you planning to keep the bricks?
How many stories is the house where the chimney is?

An easy way to get rid of the bricks quickly and minimise handling is to get a piece of 200 mm PVC pipe right above/into a trailer. Also, the process generally creates a heap of dust.
goodcleanfun, Apr 14, 3:25pm
Thanks for the replies. Rereading my post I wasn't very clear in my question. My question relates to patching the hole in the corrugated iron roof. Not the chimney removal part - totally fine with that bit.

Thanks.
mm12345, Apr 14, 3:47pm
Fletcher EQR patched the hole where our chimney used to be with pieces of corro pop riveted over the top, a tube of silicone sealant, and a prayer. The prayer failed and it leaked immediately (unsurprising). After we turfed them off site, I replaced with full sheets (not long-run - so lapped under the sheet above). That part wasn't hard or expensive.
budgel, Apr 14, 4:47pm
You will need roofing iron that is long enough to tuck under the sheet above where it crosses the purlin, and reaches down to the purlin below the chimney gap, and enough sheets to cover the width. If there were any purlins that butted up to the edge of the chimney, fill the gap by making the purlin run continuous. This can sometimes be achieved by running a piece of purlin timber across the rafters directly above or below the purlins that were cut away for the chimney, it saves having to make an awkward fit between the cut purlins. If you roof is nailed on, a piece of galv waterpipe laid in the corrugation is the ideal size for using under the hammer you are pulling the nails with. It prevents damage to the iron.

One other thing, if it is an old roof, check that there are the same number of corrugations per meter across the sheets as your patch will have, If not you will have to get some that matches.

Funny how we still call it roofing iron when in fact it is steel!

Good luck!
echoriath, Apr 14, 5:13pm
Your question was clear enough. In my experience patching the roof is the easy bit, though as someone rightly pointed out, the age of the iron could be an issue.

Further to the difference between iron and steel, there is also a tendency to call aluminium "alloy", but that term could be used much more broadly, including to describe steel.
goodcleanfun, Apr 14, 11:53pm
Thanks guys. Really appreciate the input. Learned a few things in ths thread!
aj.2., Apr 15, 4:02am
OP, if you need to cut down the corrugated iron to length, you don't have to cut it right across, too easy to cut your hands, if using hand snips.
Just place the sheet on the ground, mark the length you need, then snip, in to the second ridge.
Then place a board on the sheet across it, and grab the shorter piece of iron, and give a big up wards heave, it will rip across the iron, and if done correctly will be with in a few mm of square .
goodcleanfun, Feb 3, 9:57am
Awesome tip. Thanks.