Short term roofing solution

A bit of a random question, but can anyone recommend a cheep roofing solution that will last a couple of years.

We moved into a property last year which came with a large garage/workshop 4.5m x 8m + a 5m lean too at the back(with asbestos roof but that's fine). The main roof (4.5m span and 8m long) is supported on 5 roof joists made of 4x2"'s and 2x2" rafters at 22" centres it is then clad in T&G boards to tie it all together before felting. The recent bad weather has started lifting the roofing felt off (which has also been install in vertical strips not horizontally, and by the looks of it there are at least 3 layers of old felt underneath). My original plan was to remove the old roof back to wall plates and put a new pitched roof on, I've now found that parts of the long timber walls are badly rotten at the bottom, where soil has been piled up too high against it for years. The base plate and the bottom few inches of a number of uprights are all rotten. I am planning on pulling it down and rebuilding it completely in a couple of years when time and money permit but, in the meantime it's a godsend for storing my tools/ materials and as a dry space to do stuff while I work on the house.

I've priced up a couple of options, IKO green mineral roofing felt around £300-400, but this will be thrown away in a couple of years. Alternatively i could use the plastic coated metal sheeting 32/1000 box profile around £500-600 and i could reuse it afterwards. Due to the extremely small roof rafters and the spacing between the joists and the fact they have dropped about 5" in the centre, i don't really want to walk on the roof. I'll remove as much of the old felt to reduce the weight on the roof. I'm also concerned about the T&G close boarding underneath being rigid enough to support the felt without it moving and tearing the felt, again ideally new OSB boarding would be best but that's a lot of extra money and weight to put up there. I could add a few new 4x2 or 6x2 trusses in between the existing, but it's all money id prefer to spend on the new building, unless i could reuse some if it? I'd also struggle getting the foot of the new rafter between the wall plate and the T&G boarding, i measured a gap of about 1.5", so i'd have to reduce the size of the end of the new rafter down to 1.5" to fit

A friend did suggest a large tarpaulin and some battening to fix it in place, but I've found the modern woven tarpaulins start to leak after a short while and i'll be no better off.

Any suggestions are very welcome

Thinking outside the box, a large cheap tent or gazebo erected inside (uprights cut to suit) would protect your gear, it does not need to be super quality as it will not get wind or sun on it.

Just had a thought. If i run a large timber down the centre of the roof to support the middle of the joists i can use much smaller joists, the only problem is i'd need a largish timber 7+ meters long, are these available and are they astronomically expensive? I could use a shorter one and just live with a post in the middle, but not ideal but it's only temporary so i could live with it.

Sorted for £67.00:

https://www.amazon.co.uk/Pond-Liner-8m-YEAR-GUARANTEE/dp/B001EBWLYW

(not including tile batten to fix around the edges)

Andy

HERTS P&D said:

Sorted for £67.00:

https://www.amazon.co.uk/Pond-Liner-8m-YEAR-GUARANTEE/dp/B001EBWLYW

(not including tile batten to fix around the edges)

Andy

Click to expand...

that sounds like a realistic option

jamesBen80 said:

A friend did suggest a large tarpaulin and some battening to fix it in place, but I've found the modern woven tarpaulins start to leak after a short while and i'll be no better off.

Any suggestions are very welcome

Click to expand...

I used a roll of 1200 guage DPM -it comes in roll 25m x 4m to protect an unfinished shed -I had it one there for 3 years whilst I waited to add a garden office to it.
I used 4 x 2 and 6 x 2 to creates falls -I used timber which I then re used in the build -even if it gets a bit wet, treated timber will be fine for quite a few years

you need to spend time fixing it down with 50 x 25 battens and create a fall on it. just fix at either end


tarpaulins arent that good unless really tightly fitted -and folds or creases will fill with water

make sure the plastic of pond liner goes over the sides a bit and is screwed down all the way around or high winds will rip it off

Couple of great suggestions i'll look in to them. I think the pond liner from amazon is that woven stuff that starts to leak when it's constantly flexed by the wind, but the DPM is a good call as it will last a couple of summers before the UV breaks it down i might even have a roll somewhere i can start with now to protect the worst end. I've started pricing up the timbers but due to the span and rafter spacing of 550mm i will need 47x150 rafters and 63x220 joists.