Flat roof- preventative maintenance

[truck71]

Hi Folks, decided to clear a load of moss from my extension flat roof yesterday- given nothing has been done to it in 10 years it looks in remarkably good condition. However, there are some very small cracks in the ashfelt (not split, just surface cracks) and some areas of gravel have got swept up with the moss. So, a couple of questions;

a)Is there any preventative maintenance I can do to help prolong the life of the roof?
b)Is it worth sweeping the old gravel off and replacing with new? Or at the very least should I replace the gravel that’s come off?

Any advice greatly appreciated.

[roofer]

That's very close to its sell by date. Asphalt loses its oil content over time, along with its ability to expand and contract. Prime it and put a layer of good torch on over it, and you'll see another 10 years easily.

[guindilias]

Or for a quick, cheap and temporary fix that'll last a few years - take off the gravel, give it 2 or 3 coats of decent bitumen paint like this - http://www.taindustrialpaints.co.uk/shop/boat-barg... , and leave the gravel off. That stuff is fairly expensive, you will be able to find cheaper.
I've been keeping an old corrugated iron barn roof waterproof with the stuff for about ten years now! Make your first coat thin as a primer, and the next two coats thick to actually fill the cracks. Works a treat if you are on a budget.
Another cheap option is to use that stuff the gyppos try and pass off as driveway sealant - it's the same thing but cheaper. One coat will do it, just dump the whole lot down and brush it out with a yard brush. Watch the weather, the stuff can take a while to dry.
And don't put gravel down on top of either.
If you have a Tar distillers anywhere close by, they'll sell you a drum of the stuff for about £70 straight from the works. And if you do that - shove rags soaked in any old oily stuff (engine oil, WD40, white spirit, your favourite oil based butt plug lube) down any drains you have on the roof, with a bit of good old blue rope dropped down the downpipe so you can pull it out from the bottom once the stuff starts to set. Otherwise you'll have nightmare tar-filled gullys...

[V8RX7]

I'd go with Roofers suggestion, in the drier weather - because once it starts leaking it will cost 3x more

[roofer]

The Bitumen paint in the link is solvent based. It will break the Asphalt down further. Odd they recommend using it on Asphalt.

[PositronicRay]

Hi Roofer, We've a flat roof (felt I think with gravel) one above an attached garage one above a G/F extension and one above a dormer. No problems so far, but we've lived here 12yrs without any maintenance they could be 30yrs old. Anything we can do to stave of the inevitable?

[truck71]

roofer said:

That's very close to its sell by date. Asphalt loses its oil content over time, along with its ability to expand and contract. Prime it and put a layer of good torch on over it, and you'll see another 10 years easily.

Thanks for that, sounds grand. What will I need for each of those stages, I'm assuming primer is a tar based product and the torch is the gravel? Excuse my ignorance, I'm new to roofs. Cheers.

[roofer]

PositronicRay said:

Hi Roofer, We've a flat roof (felt I think with gravel) one above an attached garage one above a G/F extension and one above a dormer. No problems so far, but we've lived here 12yrs without any maintenance they could be 30yrs old. Anything we can do to stave of the inevitable?

No, just don't walk on it to check it. You'll see splits in the drips around the perimeter, that's an indication it's starting.

[roofer]

truck71 said:

Thanks for that, sounds grand. What will I need for each of those stages, I'm assuming primer is a tar based product and the torch is the gravel? Excuse my ignorance, I'm new to roofs. Cheers.

Torch on is a layer of felt, primer helps it bond.

[Mr Pointy]

This sort of procedure?

https://www.youtube.com/watch?v=4CsTbXdERSU

[truck71]

roofer said:

Torch on is a layer of felt, primer helps it bond.

Ah gotcha. So I've got a mate who runs a builders merchant so I can get the materials at a decent price, will I need some kind of gas torch to apply the felt? Also, what's the purpose of the gravel, is it essential to replace this as well? I'm assuming dry weather is essential, is outside temperature a consideration? Many thanks.

[paulwirral]

Pay a roofer to do it , you'll wish you had when you watch your house burn down ! The gravel is there to
1 keep the surface cool
2 reflect uv rays
3 stop you seeing how bad the workmanship is , roofer will confirm this !

[PositronicRay]

roofer said:

PositronicRay said:

Hi Roofer, We've a flat roof (felt I think with gravel) one above an attached garage one above a G/F extension and one above a dormer. No problems so far, but we've lived here 12yrs without any maintenance they could be 30yrs old. Anything we can do to stave of the inevitable?

No, just don't walk on it to check it. You'll see splits in the drips around the perimeter, that's an indication it's starting.

Thanks.

[truck71]

paulwirral said:

Pay a roofer to do it , you'll wish you had when you watch your house burn down ! The gravel is there to
1 keep the surface cool
2 reflect uv rays
3 stop you seeing how bad the workmanship is , roofer will confirm this !

Yep you're probably right. However, I'm about to take a year out of work and fancy expanding my skill set- my labour is free so it's materials and equipment that I'll need. And a not insignificant amount of know how of course.

[paulwirral]

The roofing company will have public liability insurance , your house insurance may question why you are burning your flat roof covering !
It's very easy to leave an un seen fire with a blow lamp , I speak from 20 plus years experience , as will other felters .

[Wacky Racer]

Get rid of all the dust, stones etc, and give the felt two liberal coatings of Isoflex black liquid rubber, (leaving 24hrs between coats) best choose a dry spell in spring......

Been using this stuff for 30 years, not cheap but never let me down yet.

Failing that, rip all the old felt off and start again with heavy grade green mineral.

However, I'm sure "Roofer" has far more experience than me in these matters....

[truck71]

Wacky Racer said:

Get rid of all the dust, stones etc, and give the felt two liberal coatings of Isoflex black liquid rubber, (leaving 24hrs between coats) best choose a dry spell in spring......

Been using this stuff for 30 years, not cheap but never let me down yet.


Failing that, rip all the old felt off and start again with heavy grade green mineral.

However, I'm sure "Roofer" has far more experience than me in these matters....

That sounds interesting and more in line with my capabilities. The roof looks to be in really good nick, no peel or splits anywhere. I'll take some more comprehensive photos and see what the collective think.

Totally get the fire risk/ insurance thing with laying new felt not to mention a total amateur involved. What could possibly go wrong. .

[paulwirral]

truck71 said:

Wacky Racer said:

Get rid of all the dust, stones etc, and give the felt two liberal coatings of Isoflex black liquid rubber, (leaving 24hrs between coats) best choose a dry spell in spring......

Been using this stuff for 30 years, not cheap but never let me down yet.


Failing that, rip all the old felt off and start again with heavy grade green mineral.

However, I'm sure "Roofer" has far more experience than me in these matters....

That sounds interesting and more in line with my capabilities. The roof looks to be in really good nick, no peel or splits anywhere. I'll take some more comprehensive photos and see what the collective think.

Totally get the fire risk/ insurance thing with laying new felt not to mention a total amateur involved. What could possibly go wrong. .

What did the dog say when someone shoved a gallon of petrol and a lit match up its arse ?woof
much like the fire and torch on felt scenario .
It's not brain surgery but il hold my hands up and admit my first few attempts were pretty rubbish
Good luck

[truck71]

truck71 said:

Wacky Racer said:

Get rid of all the dust, stones etc, and give the felt two liberal coatings of Isoflex black liquid rubber, (leaving 24hrs between coats) best choose a dry spell in spring......

Been using this stuff for 30 years, not cheap but never let me down yet.


Failing that, rip all the old felt off and start again with heavy grade green mineral.

However, I'm sure "Roofer" has far more experience than me in these matters....

That sounds interesting and more in line with my capabilities. The roof looks to be in really good nick, no peel or splits anywhere. I'll take some more comprehensive photos and see what the collective think.

Totally get the fire risk/ insurance thing with laying new felt not to mention a total amateur involved. What could possibly go wrong. .

Quick update, spent the last couple of days clearing the gravel, hosing down and applying the rubber paint. What a great product, took no time at all to cover a 3.5m x 5.5m area and looks great. Hardest part was getting the gravel down, through the house and off to the dump. Total cost was £160 for the rubber and a tenner for the application tools.