Builders advice

greenface

Thanks for reading . I have a utility room downstairs single story extension about 12 x 8 . The roof is concrete about 4 or 5 inches thick . I'm tempted to try to take it down and put a tiled roof above . Let in some light with a velux and a bit a of height inside the room . Anyone done it ? How difficult is it to breakthrough . the new roofing part isn't a problem once cleared just not seen one taken down .

Furts

Cannot say without seeing it, but it could be an in-situ reinforced concrete roof. Basically the walls would have been built, a plywood/softwood strip soffit put across, then reinforcing steel and pour the concrete.

Your problem would be the concrete will be as hard as rock after these years, and you will need a breaker. This will be slow going because of the reinforcing tieing the concrete together. In the process the vibration will weaken your walls, and they could collapse.

You could disc cut out where you want a Velux. You will weaken the roof, possibly considerably. However, my gut feeling is you would get away with this.

Kiran

You've had good advice above, only thing I would add is the balance of probability is that the reinforcement is only mesh so for a small velux type roof light you would be ok. If however you are thinking large glass roof type then you need to take advice as to whether or not the roof is tying the walls together. I'm assuming the roof is flat so you also need to investigate a robust waterproofing detail between the concrete and the roof light up stand. you can get a diamond driller to cut it all out which will avoid vibrating the roof too much. Day rate is around £200-250 around here

Kiran

I've just realized that you are talking about removing the whole roof and replacing so you can scratch some of my previous post. However I think it would be possible to add roof lights to the existing concrete roof if it is in a reasonable condition

Hintza

The question has to be why? Sounds like a total nightmare at huge cost.

You really need to decide if any benefit is worth it.

brightontraveller

Breaking out concrete roofs can be problematic you can try supporting and cutting small sections at a time, or breaker although this can damage existing walls, I’d probably use rebar locator for size locations of reinforcing see if velux or light well would fit without weaking structure also see if I could go down for room height ,
Removing a roof that does its job keeps water out and replacing with one that might not ? Could be a costly exercise for a bit of extra light.

27cool

Have you any idea of the weight of concrete you are proposing to remove. I can tell you, it's a hell of a lot.

greenface

I'm with you all .Thanks for the advice . I'm thinking of removing the lot and understand the walls could be affected . I'm going to pass on it I think . My utility room is damp so first thoughts was to knock off all the render outside . and have a good look . Clear away the inside plastic cladding (about 5 years old ) It has a solid floor and decent tiles that don't look in anyway affected by damp . Think I will cover the concrete roof .pop a running gutter onto it and renew the flashing . I don't fancy knocking bells out of a roof I'm standing on either . I will try to pop a pic off my phone but knowing my computer skills . don't hold your breath . thanks again