Can you convert a loft of steel framed house?

hobbeskat

Specifically Trusteel 2? It's a very sizeable, high loft.

EachPenny

You will need to get professional advice as it is a complex question to answer, and the answer may depend on the condition of the specific house you have in mind.

If it is of the type pictured on this site https://www.bisfhouse.com/trusteel-mkii-steel-framed-house/ then I'd say it was unlikely to be possible.

The load on the loft floor would be supported by the "ceiling collar-beam" which appears to be attached to the main rafter by a single bolt either end, and suspended in the centre by a tie-rod connected to the ridge.

I would guess that the members and connections were designed to take the load of the roof and the ceiling and very little else. I might be wrong, but my understanding is that designs like this were developed for economy of material, which would preclude significant overcapacity.

The roof and ceiling loads are then carried down to ground level by stanchions rather than the walls, so again the question would be whether these stanchions have the capacity to take any additional load in the loft.

A quick read of one of the reports on that site suggests there may be issues with corrosion (which reduces load bearing capacity) so even if the original design did have some overcapacity, subsequent corrosion might have reduced that to nothing.

If it was me I'd work on the basis that the cost of getting the steel structure surveyed and employing a structural engineer to do the design work would leave me with a very expensive loft conversion, assuming that it is possible at all.

Could you add an extension instead?

hobbeskat

Thank you, that's very helpful! We have a steel survey and the steel is in perfect condition.