Replacement roof over an existing roof

[Matheson]

I live in a building with four other flats and our decramastic roof is now 50 years old and is rusting and has deteriorated to the extent it needs to be replaced. Two flat owners favour the option of putting new roofing tiles over the top of the existing roof. I don't believe this is a good idea for a number of reasons. This appears to be a short term solution and not does not have my support. Has anyone had any experience with doing this and does anyone have some advice?

[SimonW]

I have no experience with this sorry, but I would have thought the existing roof trusses would have been engineered to hold a certain weight, so putting an extra layer of roofing on a roof structure not designed and engineered to support that extra weight would seem like an absolute no-go to me.

Why are they so against removing the old surface? I'd imagine any competent roofing contractor and his crew could probably strip and replace the entire roof in just one day depending on the size.

[Aston]

I don't have any experience with this but my initial thought is why on earth would they want to do that? Seems like a crazy idea to me. I wouldn't be surprised if it were to cost more to lay the new tiles over the old ones. I don't think the weight would be an issue but the existing guttering may need to be lifted because it may end up being too low. I'd be inclined just to get some quotes and get feedback from roofing contractors, they will tell you if it's a good or bad idea.

[erinak]

I live in a building with four other flats and our decramastic roof is now 50 years old and is rusting and has deteriorated to the extent it needs to be replaced. Two flat owners favour the option of putting new roofing tiles over the top of the existing roof. I don't believe this is a good idea for a number of reasons. This appears to be a short term solution and not does not have my support. Has anyone had any experience with doing this and does anyone have some advice?

I suggest you ask 2 or 3 certificated tilers for their advice/recommendations in writing with quotes whether to tile over or to replace. I cannot see them opting to tile-over existing - it doesn't seem logical. Are you and the other residents the owners? Because all four would need to agree, but you only have 3, so maybe the 4th may be the decider.

[Nick G]

Yuk, no. Get a roofer, replace, no worries for many more years.

I live in a building with four other flats and our decramastic roof is now 50 years old and is rusting and has deteriorated to the extent it needs to be replaced. Two flat owners favour the option of putting new roofing tiles over the top of the existing roof. I don't believe this is a good idea for a number of reasons. This appears to be a short term solution and not does not have my support. Has anyone had any experience with doing this and does anyone have some advice?

[John the builder]

This approach was common and in my view wouldnt be less durable or the weight be a problem but the concerns are with the state of purlins and their appropriate size, uplift fixings etc. Roofers generally donty do this now and removing the existing isnt such a big deal?

[Simmo]

Definitely remove and replace...unless there's another reason to leave the existing roof in situ? Potentially asbestos in the glue?