Loft room

29 Jul 2010
Reaction score
United Kingdom
Hi everybody,
I'm, looking to convert my loft into a usable room and was hoping that somebody could help with a question..............
House was constructed in 1890 (terrace) so has a very large loft space free from roof trusses and all the annoying limitations of newer houses. Roof construction is fairly standard for a house of that age with 2"x3" rafters with 9"x3" purlins at half height and 2"x3"ceiling joists, ceiling joists sitting on external walls and supporting wall running across the middle of the house. 2 support beams run between the side walls in the loft at mid point across the front and back rooms which the ceiling joists are attached to. Following this so far?
What I am looking to do is tie these beams to the rafters/purlins using 2"x2" uprights then hang 2"x6" joists between the beams to give a new floor level. At mid point, the new joists would be supported by the central supporting wall (which would be built up to suit) so the spans would not exceed 2.6m at any point. The new joists would sit approx 1/2" above the existing ceiling joists. Would this work? I understand that the loading of the new floor could cause the support beams to deflect leading to cracks in the ceilings below which is the reason for tieing them to the rafters/purlins making the structure pretty solid. Forgot to mention, the beams are 9"x3" and 7"x2 1/2".
Any advice would be appreciated
Sponsored Links
Employ a cheap structural engineer. You purlin's are unlikely to be man enough to suspend the floor from.
I'm not looking to suspend the floor from the purlins - the floor would be suspended from the 2 big beams that the ceiling joists are attached to. I was just thinking that tieing these beams to the purlins would give them some extra support and prevent them from sagging at all and possibly cracking the ceilings downstairs
Sponsored Links
The new beams would need to be taken back to load bearing walls and best to avoid using the purlins as any form of support for these beams.. all steel beams are designed for standard deflection tollerances for plaster finishes..

Best employ an SE

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local