Loft conversion - steels

[Vickiloftconversion]

Hi

I'm planning a loft conversion in a 1973 house- Velux conversion no dormer. Loft has 2 fink trusses - space is 10m by 7m (useable width 3.4m). There are 2 load bearing walls each 3.5m from external walls. So 3.5m (external wall to LB), 3m (LB to LB), 3.5m (LB to external).

I've had a SE do a report but I'm concerned that is not accurate - LOTS of UB including ridge steels and supporting posts- everyone I've spoken to has said there is too much steel and builders won't even quote! I'm planning a new SE but want to do my research.

I'm thinking at 2 UB floor level, gable to gable supported at end walls on padstones and in the middle on load bearing walls, with floor joists hanging from the UB. Stud walls under roof trusses with packers and ceiling ties. OSB over new floor joists. Does this sound reasonable?

The space will be two small bedrooms for my daughters with an en suite bathroom.

I'm planning to insulate the roof with kingspan and 12.5mm plasterboard to the eaves (although also considering PRI plasterboard) and use the space under the eaves for storage.

Very rough drawing below (please be kind this is not my field!). I'd be very grateful for advice!!

 

[Wayners]

I took roof off and dropped trusses on so no steels so can't help you.
I took advice and that was the best option I thought.
With the velux go for small as you can.
They are like radiators in the summer and we put outside blinds to reduce the rain noise. We have 3 large ones which is my biggest regret

 

[freddiemercurystwin]

Are there existing purlins, got some photos of the internals of the loft? Given the scant information I would have expected only two steels, beneath your new stud walls, which would also act as structural walls (all timber) to provide support to the rafters. What's the existing height from the top of the existing ceiling joists to the underside of the ridge?

 

[Vickiloftconversion]

Thank you for replying!

Height is 2.6m. Yes there are purlin.

 

[Vickiloftconversion]

Sorry pics aren't very good

 

[freddiemercurystwin]

Hmm, well assuming you know you'll not end up with particularly high ceilings aside, then that's a very traditional loft, so the stud walls would normally sit beneath the purlins to support them, then the trusses and other supporting struts can be lost. No need for a ridge beam, employ a different SE.

 

[Vickiloftconversion]

Thank you so much!! That's exactly what I needed to know!

 

[Vickiloftconversion]

Thank you

 

[catlad]

They are like radiators in the summer and we put outside blinds to reduce the rain noise. We have 3 large ones which is my biggest regret

You can get noise reduction velux skylights.