loft structural strength

[adwt2004]

I need to fit a hot water cylinder / cistern in the loft space. I have no where else in the house where it can go. The tiny airing cupboard won't accommodate. The loft is huge but the issue is with the strength...

I have 4 by 2 joists and the tank/cistern capacity is 138 litres plus weight of empty tank so all together around 180kg ish. There is 1 wall seperating the bedrooms that I presume is load bearing (Wall labeled A).

Can you give me any ideas of what i can do? Could I run new joists from wall A to wall B of 8 x 2 thickness and then put a floor in. This would create a platform over in the right hand side. Would that work?

To explain: My neighbouring walls are the top and bottom of the picture. I haven't drawn them because I cannot use them. The span accross from wall A to B is 4.5 Metres

can you guys help?

 

[noseall]

i'm fairly sure that if you cross battened the existing joists with some more 4x2" and made them say 6 foot long, it would adequately support the cylinder.

 

[adwt2004]

I could be wrong about the joist sizes, they may be 3 by 2, i will check when i go home soon. Would the same advice still apply if this was the case?

Would fitting new much thicker joists next to the old and having them lay on the edge of each wall spanning 4.5m be a bad idea?

 

[noseall]

I could be wrong about the joist sizes, they may be 3 by 2, i will check when i go home soon. Would the same advice still apply if this was the case?

Would fitting new much thicker joists next to the old and having them lay on the edge of each wall spanning 4.5m be a bad idea?

3x2 does seem a wee bit lean.

fitting thicker joists next to the old would be an ideal scenario. will you have the headroom to haul 4.5m joists into the loft?

 

[masona]

See your other post here

 

[adwt2004]

Sounds good but i've just noticed that between point A & B there is a larger piece of wood that sits on top of the joists and runs in the opposite direction to the picture. There are two of them with the other being between A and the far left. They are sitting in the walls and cemented in at either end which are at the top and bottom of the picture and are 4 x 2 size.

It means i won't get a clear run with a 4.5m joist between point A & B. It is blocking it and i don't want to remove it because i'm guessing it is critical to the structure. I will post a picture.

Really stuck now

 

[markie]

Once you post a pic we'll will be able to give you better advice.

 

[adwt2004]

The extra insulation is above where my rectangle tank is. There is a single brick wall (not double - was mistaken) underneath the next bag. and i was planning on running some 8 by 2 " joists from it to the far right where my soffits are. But you can see there is some kind of strut that fits into the wall either end running opposite to the joist direction which is just past my chimney breast.

Any ideas what i can do? The joists are 3 by 2 and that strut is 4 by 2. There is 1 more strut that is a meter away to the left of the next bag that also is mortered into the wall.

 

[noseall]

those 'struts' are called ceiling binders or summil beams and are there to take the whip out of the ceiling.you mustn't put any additional load directly on top of these.

 

[Deluks]

Tricky one. What you could do is run new joists from a to b, but packing each end up so that it sits above the ceiling binder. So 3 2x4s, (or a 6x6) lying directly across the brick wall, and the same again at the other end. Only problem is of height at the other end due to the roof pitch. Although being so close to the outer wall, that end of the ceiling joists will transfer most of the loading into that wall.

You will also need BIG timbers to carry that load over 4.5 metres. It would probably be cheaper to get down to a scrap yard and get a couple of reclaimed RSJ's. But you'd still have to get them into the roofspace.

 

[Deluks]

DOH! Sussed it.

1) Lay a 6x6 atop brick wall (point a)

2)Bolt a timber wallplate to the other brick wall* at the back, level with the top of the 6x6.

3) Lay new joists diagonally across each of these and put your tank onto this platform.

*is that the one you say you can't use? Why not? I'm not sure rawlbolts come into the party wall act. It's just an extreme version of banging a nail in for a picture.

 

[gangman]

If the walls below are load bearing, then build up the wall running with the joists with some bricks then run your timbers off this wall and onto joist hangers fitted on the party wall. You can take out a bit of a bed and use masonary hangers or drill and plug jiffy hangers.

 

[adwt2004]

Thanks for your advice and tips. lots of things i hadn't thought of!

Thanks guys