No struts in 1900s terrace roof

[Joelb999]

Hi, first post here.

I am currently looking into making my loft more usable. When I bought the house it appeared to have a non-reg loft conversion of sorts done to it - rooflight window, floorboards, plasterboarded and plastered rafter ceiling etc.

On closer inspection I can see it's been a total bodge. I won't go into all the details as I can fix most of it myself - this would be a LONG post if I mentioned all faults (I know - 4x2 floor joists! - attached to the 3x2 ceiling joists too!!!!)

However, I've noticed that there are no diagnol struts running from the purlins, just upright studs from each rafter to the binder (which is not on top of load bearing walls).

I've had the house for 4 years now, no disasters have occurred.

I'm just wondering if I should somehow get the load from the purlins to the load bearing walls in the middle of house.

Ive uploaded a couple of photos to give idea of what I'm faced with.

Any advice would be appreciated.

Thanks

 

[blup]

Struts are replaced with dwarf stud walls to make space for the loft room, it'll depends on the structural calculations for the changes - it looks as if yours did not have any.

Did your survey pick up on this?

Blup

 

[Joelb999]

Hi Blup, thanks for replying. These upright studs that you can see in the photo did have plasterboard attached to them forming walls, so that makes sense in keeping with your dwarf stud wall thought.

In terms of calcs, I haven't seen any. I had a home buyers report when purchasing the house. Of course, with the stud walls in place, the surveyor would only have taken into account what he could see in the loft. He did go in there but didn't flag anything suspect.

I want to lay 6x2 joists from the Em wall plates to the central load bearing walls (the two bedroom brick walls) but the binders are in the way of the extra 2 inches. Any idea how I could go about that? I know - another question. I had Ann idea of cutting it out but by bit, then laying another on top of the 6x2s but not sure if that's a stupid idea...

Thanks again

 

[blup]

AFAI understand it, as a DIYER, binders contribute to the overall structure, but the main purpose is to "stiffen" the joists spreading the load, and inhibit twist.

Which way do the joists run relative to the stud wall under the rafters, and what is their span?

Where are the intermediate walls, and are they structural (some walls are first floor only and only rest on double joists)?

A builder or structural engineer on site would be best placed to give advice.

Blup

 

[Joelb999]

Hi again, apologies for the delay in responding - I wasn't working away yesterday.

The joists run in the same direction as rafters, stud wall under rafters is at 90 degrees to that (hopefully the photos give a bit more detail - the photos are before and after, I've stripped away all plasterboard now - the roof was not reinforced to take all the weight - cowboys!)

The dimensions are as follows - width 770cm (wall plate to wall plate), length 345cm. 10 joists on each side - wall plate to each supporting wall below (both walls below Are brick walls, the span from wall plate to one supporting wall is 330cm and the other is 340cm - although having measured these that doesn't work out as between the bedroom walls there is approx 1 metre of that makes sense to you.

 

[blup]

When you say width, you mean in the same the direction as the ceiling joists, and that these joists are perpendicular to the wall(s) below?

Blup

 

[Joelb999]

You got it. And those walls below are brick, with wooden wall plates on them

 

[blup]

Nail holes in the purlins and ceiling joists would be clues as to the existence and location of struts that might have been removed.

The stud wall plate will offer rigidity that removing the binders might lose, you could put in noggins between the rafters as an additional measure. I have 4x2 joists with about the same span as yours, older properties tend to have better quality timber that was slow grown, and so a better load bearing capacity than todays.

But at the end of the day, especially if the loft is to be used for storage or habitation, you will need expert advice, as its just not possible to identify what's needed from the photos alone.

Good luck!

Blup

 

[Joelb999]

Thanks Blup, that's a good idea to look for nail holes!

Thanks for all your help, have a good day sir.