Loft strengthening - specific area

[Maccca99]

Hello, I would appreciate any advice on the following:

I want to have a side-opening velux window fitted in my loft, to use a large telescope weighing 70kg.

To support the weight of the telescope I think I would need to have joists added on load bearing walls.

Could the joists be added for a specific width to accommodate the telescope, approx 1 metre, or would the whole loft need to be done?

Thanks

 

[blup]

Loft joists take the weight of a human occasionally, and the weight of say a water tank, which is much heavier, permanently, so it is probably sufficient to spread the weight on some ply spread over several of the existing joists. It will be different if you are planning evenings up there with the local branch of the sky at night.

Blup

 

[JohnD]

it depends on the depth, width and unsupported length of your existing timbers, and their spacing. Post some pics and measurements.

18mm ply, screwed down, may be adequate, or you might need counterbatttens running at right-angles to the existing timbers, to spread the load and add rigidity.

Is the ceiling below, plasterboard or L&P?

old ceilings are particularly prone to crack (or fall down).

 

[HERTS P&D]

Come on Macca, spill the beans, any UFO's or sexy neighbours?

Andy

 

[Maccca99]

Would be great if i don't have to make major adaptions, will check the current joists, it's a bit difficult as the loft has basic boarding already. Cheers for the suggestions

Well Andy, I do have heavenly bodies in mind but they're a few light years away unfortunately lol!

 

[HERTS P&D]

18mm ply sheeting over your boarding should be fine.

Andy