Garden Office

[AGW]

Hi just looking for a little advice in respect to a Garden Office that I am currently building.

 

The floor span is 4.8m x 4m and the plan is to have a shed partition built into the rear of building which will be 1.8m x 4m and to have the front section house the Garden Office.

 

I two questions I have are as follows;

 

1) What size of roof joists should I use?  I was planning on using 5' x 2' roof joists but a friend had said they may require to be bigger to prevent bowing.  Is this the case if there is a supporting stud partition separating the shed section @ 1.8m?

 

2) Secondly I plan to have 3m bifolds on the front elevation of the building.  Given the floor span is only 4m I believe I will need a 160 x 80 x 5.0 rectangular hollow section to support the roof section.  Will this be sufficiently strong enough?

 

Any assistance provided will be greatly appreciated.

[riboid]

1. It depends on your roof finish?  Will you tile it, if so, then you will have to gauge the roof structure to allow for the weight of the tiles.

2. You propose to use steel as a lintel?

[AGW]

Hi thanks for replying.

 

1) I intend to 18mm OSB over the joists and then fit a rubber roof.

 

2) Yes I plan to use the steel as a lintel.