Older style garage with asbestos roof

[ts2698]

Hi all, could do with a little advice. Basically cut a long story short I hire a garage to keep a classic car in. It is block built with asbestos sheets. From January this year when I started renting it until around 2 weeks ago it has been great. All I do is sheet my car over with an Egyptian cotton sheet to keep any bits off the car that may drop (under vibration from animals walking on roof).

However the last couple of weeks I've suddenly noticed a lot of condensation on each of the ridges of the roof sheets and the back wall seems damp but the two side walls bone dry. I've asked the owner to check the guttering and he says the guttering is fine but it looks like there is a lot of moss on the roof. Could this be causing the condensation? If not another thing I've noticed along the back wall one corner close to the floor seems quite damp, could this mean moisture is coming in from the rear, climbing the wall and going to the roof and turning into condensation?

Is there something I could paint on the interior wall that looks damp and on the inside of the roof? Something that would be classic car friendly that wouldn't split and crack off? Just frustrating at the minute as I can no longer sheet my car over as the condensation is dripping on the sheet causing a damp sheet and don't want to leave a damp sheet touching the car

 

[Tigercubrider]

Doing any painting might be an issue with the landlord?
Bitumen might work (car somewhere else for a week)

another option might be to run a line of wire or paracord end to end down the centre line.
then two more lower down off the walls.
run a tarp across the centre, creating a pitched roof to train the moisture off to the sides.

possibly some bias to one end, allowing water to drain to two points?

paracord is very strong, I use it a lot. Use wire tensioners to get the cord tight.
The cord holds 550 lbs in a 4mm cord.

there is a thing called a Carcoon, basically a huge bag that holds a car.
probably needs power.

last thought is find some cheap /second hand gazebbo frames as tarp support?

 

[ts2698]

Doing any painting might be an issue with the landlord?
Bitumen might work (car somewhere else for a week)

another option might be to run a line of wire or paracord end to end down the centre line.
then two more lower down off the walls.
run a tarp across the centre, creating a pitched roof to train the moisture off to the sides.

possibly some bias to one end, allowing water to drain to two points?

paracord is very strong, I use it a lot. Use wire tensioners to get the cord tight.
The cord holds 550 lbs in a 4mm cord.

there is a thing called a Carcoon, basically a huge bag that holds a car.
probably needs power.

last thought is find some cheap /second hand gazebbo frames as tarp support?

Thanks for the reply, some great ideas there, bitumen did cross my mind actually especially for along the bottom to seal. Might have to consider the cord idea

 

[Harry Bloomfield]

I've asked the owner to check the guttering and he says the guttering is fine but it looks like there is a lot of moss on the roof.

If the roof, doesn't have much of a slope, then moss can build up to the point where it blocks the corrugations enough, that rain can build up and overflow the overlapped joints in the panels. Other than that, asbestos can become porous, develops cracks easily. In really cold weather, condensation can build up on the underside, even frost, which drips as it thaws.

 

[Old Salt]

Its also been really humid the last couple of weeks even when its not p*ssing it down. Is there lots of ventilation? Can you improve ventilation?