Fixing into overhead concrete beams

[Licklieder]

I will be shortly fixing battens to the ceiling of my flat which is of a (1968) block & beam construction, or equivelent, with the base of the blocks sitting nominally flush with the base of the beams, in order to insulate & drop the ceiling.

The beams are ~150mm acroos the base (got no idea about height) and approx 3m in lenght, and I am assuming will be reinforced. Is anyone able to give me some guidence on where to expect the rebar ? I'm guessing there are two or three running the length, but have no idea of the spacing. If three, i would assume even spacing at 37.5, 75 and 112.5mm from one edge, and if two, i'd assume at 50mm and 100mm.

Whilst i am expecting to have to drill some pilot holes, I would like to minimise how many I drill so any pointers as to where to hit would be appreciated

 

[Paulg31]

Hi,

I'm afraid I can't really give you any advice on where the reinforcement will lie but beams for beam and block are normally prestressed so they'll have a number of tensioned wires in called tendons. Have a look at http://www.milbank.co.uk/wp-content/uploads/2014/11/Beam-Block-PT.pdf for an example. There could be 1, 2, 3 or more in the bottom.

Paul

 

[tony1851]

As above, these beams are pre-tensioned and drilling them is not recommended in case you hit a wire.

 

[maltaron]

Not over familiar with beam & block but would it not be more sensible to fix to the blocks?

 

[Licklieder]

As above, these beams are pre-tensioned and drilling them is not recommended in case you hit a wire.

Not over familiar with beam & block but would it not be more sensible to fix to the blocks?

When I spoke to the landlord / management agents about the work I am doing and how to fix into the ceiling they said to fix into the beams - hence the question. Looks like i'll just have to do some pilot holes and see what's up there.

 

[Burnerman]

Hire a cartridge hammer?
These potentially lethal tools fire a nail through a timber lath, direct into concrete.....mine fired studs into steel! Amazing.
John

 

[cjard]

Hire a cartridge hammer?
These potentially lethal tools fire a nail through a timber lath, direct into concrete.....mine fired studs into steel! Amazing.
John

Indeed; trying to have a conversation with my timber framers while their apprentice was nailing a piece of wood to a 4mm thick steel hollow section steel using one a Hilti gun was darn near impossible, but very impressive that it could drive a nail through 4mm of steel