Penetrations through a concrete living roof Aaaaagh!

[Nickfromwales]

Howdy.

I want to fit a log gasification boiler in a garage. The garage is akin to a basement, offset to the right and one floor down from the entry level of the dwelling. If the appliance goes to the left rear corner I can rise vertically and bolt onto the side of the gable, rising accordingly to clear the ridge draught. Problem is, the garage roof is the right hand 'garden' of the house  !

 

I haven't had a look as to whether its already leaky, but needless to say I need to meet or exceed its current state if I make a penetration through it. Im assuming B&B with ( water proof ? ) concrete over-pour as this is an existing turn of the century cottage. The garage, I think, is an afterthought as it looks to be built off the side of the house ( which is elevated 9' higher than street level ) but if original what would it have been ? Was reinforced concrete formwork around back in the day? 

So. Concrete core drill or series of holes and punch through to make the hole, then what? Sleeve and 'grout' with a waterproof slurry? back-fill with a resinous HR material ?Then take the flue through the sleeve with an intumescent seal and rain deflector ring? First time I've ever had to punch through a living roof, so any pointers would be appreciated. Take me now lord!

 

Cheers.   

[Triassic]

I’ve seen old reinforced concrete roofs reinforced with anything from old iron gates, narrow gauge railway sleepers, to steel bar and tubes. Maybe drill a few pilot holes in the area you wish to core drill.

[PeterW]

As per @Triassic says. Clear the soil so you get to concrete then it’s a test drill to see what you’ve got. Is the underside easier to see...?? I’d be looking to both core it wider than needed then use some sort of waterproof membrane such as a self adhesive rubber on the sleeve and the roof junction and back fill around that area with clean stone. Keep the soil clear using a bucket with the base cut out of it. Should be easy enough to put a flue through that with a collar. 

[ToughButterCup]

2 hours ago, Nickfromwales said:

[...]

I haven't had a look as to whether its already leaky,

[...]

 

Reduce your exposure to risk. Find out. Doing that will, at the very least improve the accuracy of your quote

[Nickfromwales]

12 minutes ago, recoveringacademic said:

 

Reduce your exposure to risk. Find out. Doing that will, at the very least improve the accuracy of your quote

Probably going to look at it afresh, and accept that its all or FECK all. In for a penny.......Always best to strive to meet or exceed the standards set by those before you ?