Boarding small void in loft conversion

[Alexolcz]

Hi

I recently moved into a terraced house with a dormer loft conversion. The house was built around 1900. At the front of the conversion there is a small void with an access hatch from the bedroom. I have attached a section of the engineering drawings from the conversion.

I would like to board this area in order to use it for storage, nothing too heavy. Due to the shape I would probably have to crawl into the space to be able to use it. My plan for this would be to install loft legs and use tongue and groove loft boards.

I would like to know if the joists will be sufficient for storage. The joists are 2" x 3" with a spacing of approx. 450mm. The joists do NOT appear to be attached to the steel beam (marked "C" on the drawing). However there is a 1x3'' running flat and perpendicular to the joists (parallel to the steel beam). This is nailed to the joists. I haven't been able to get to either end to the find out if this is attached to the party walls.

The maximum span is about 3.6m to the wall in the centre of the house. From what I have read this seems to be quite long for this size of joists. I am not sure if boarding this space for light storage with all of the load close to the end of the joist will be ok.

There are a few loft legs and loose ply-boards in the loft, indicating that it was once used for storage. Given the amount of debris on the insulation this may have been prior to the conversion.

I have tried to include all the details I think may be relevant, however please let me know if you need any further details.

Many thanks in advance for any help you are able to provide, I really appreciate it .

Cheers.
Alex

 

[Tigercubrider]

I am not in the trade

I tend to think that it will be ok- you won't be storing bricks in there.

My house was built with a bedroom partly in the eaves, so that one wall is a stud wall with a similar space behind like yours, only mine is floorboarded. I ended up cutting through the stud wall to create cupboardsrather than a crawl space.

I looked into loft legs but ended up making a system out of ply to increase the height for insulation.
Yours is quite small so maybe just celotex or insulated flooring? It spreads the load like a snow shoe

 

[Alexolcz]

Hi

Many thanks for getting back to me, I really appreciate it! Sorry for my delayed response - I have just got back from holiday. Was your house originally built with the room in the eaves? I think if that we the case the joists would have been designed to carry the load of the floor.

As mine is a converted loft the area I would like to board uses the original ceiling joist. I am therefore worried that the deflection will crack the plaster. Does anyone have any experience in how I can calculate the maximum deflection and what is allowable before the plaster will crack?

Many thanks
Alex

 

[vinn]

Your 2" x 3" joists will only allow a min of weight - so why not load the sheet o ply and watch and wait.
If no problems then extend the boarding.

 

[Alexolcz]

Thanks for you help Vinn, yes I did think of that. It just seems a bit risky!