Best way to seal crack in concrete roof.

[gaz1]

Whats wrong with using asphalt, the proper stuff which I think is sharp sand mixed with bitumen and laid with a trowel like a screed

Bob

its why i suggested tar in the first place

the problem is its half owned by him at rear and at front by someone else the issue is you have to do the lot to cure what could be your trouble

so id want to pay less for the same job

 

[frank horton]

Taxi ray
here in Crete there are many flat concrete roofs.....must run into 1000's......
we use a water based rubberised compound......
it can be brushed or almost trowel'd on....for verticals I use a brush.....
they recomend two coats with 24-48 inbetween......
I can assure u that it works great.....
our temps are from just freezing to +40*deg in the shade.....
it makes no diff if it's in direct sunshine all day......
it will go over damp conc but not v/wet or puddles......
I thought they were pulling my plonker when I first asked about a product to seal my roof......
"Water based Rubberised Compound" how times' have changed.....hahaha.....
for pourus and or dusty conc there is a water based sealer for use prior to the above....mine got two coats...looks like coloured water......
the sealer was €25 x 5ltr and the compound was £30 odd for a 9-10ltr bucket.......so cheap enough to do the other part of the roof as well.....
mine had cracks all over, a bit flakey /dusty, plus the parapet wall was not so good.....
when it rains here it's tropical and has held up, no leaks but it's only been done a year.....
a recomend from me......

 

[cheb]

Why won't fibreglass work on damp or wet concrete? Is it an adhesion thing?

How big is the roof, and how much extra would it cost to do next door's too? Is paying the extra worth it for your problem to be solved? That's ignoring the 'it's not fair' reasoning.

 

[taxi ray]

Roof is about 22 foot by 8 foot.
Job has gone from a quick repair to major work.
There will be no contribution from the neighbour.

I have lived with it for years, so I will probably do a quick fix, and leave it at that.

 

[Onoff]

I'm the king of quick roof fixes here. Our dormer roofs are proper shoddy. Had a felt roof put over another felt roof. Minimal adhesive used and the felt butt jointed rather than overlapped. The fall is minimal too

The best result was when I cleaned the roof first with No Nonsense Degreaser in a plant sprayer and hosed off. Then painted with a bfo tub of acrylic roof repair compound. Fill any big cracks with the in a tube or trowel on roof repair mastic.

I keep putting off doing the roofs properly as I'd like to extend the dormers a fraction either way. It all needs redoing, fascias, soffits, guttering, dormer cladding.

I've done the "better" side. The really bad side just has a sheet of weighted down DPM over it at the mo!

I reckon a good clean, fill the cracks with a tube of or trowel on roof repair mastic then this stuff would sort you.

20kg tub of one of the acrylic compounds on eBay for £130:

20KG EVERBUILD GREY EVERCRYL ONE COAT ROOF REPAIR COMPOUND PAINT | eBay

All roof surfaces to be coated should be sound, stable, clean, i.e. free from loose debris, dirt, dust and grease. All traces of algae and fungi growth should be removed using a stiff-bristled brush.

www.ebay.co.uk

Tbh you'll get a similar acrylic compound on there for <£100.

£10 for 5L of degreaser from S'fix

Error 410 | Screwfix

Thousands of products at low trade prices | FREE next day delivery available | 30 day money back guarantee on all orders.

www.screwfix.com

>£10, tube of fibre reinforced repair sealant from T'station (not sure how many cracks you have):

Evercryl Roof Repair

• Instant waterproofing • Fibre reinforced • Gap filling • Exterior use only Instant roof repair even in damp conditions. Fits a standard gun. 72 hour cure. 1-2kg per 1m2 average.Hazard safety codes: Xi, F, R10, R22, R36, R37/R38, R41, R46, R50/51, R53, R66.

www.toolstation.com

Clean
Hose
Fill
Paint


Buy a cheapo broom like in my picture.

Be prepared to bin any tools you use.

Have a spare bucket with bin liner in to dump the used broom into.

Roughly divide the area up into 1m2 with chalk or a Sharpie. Dollop however many litres per m2 and spread with the broom.