Victorian Terrace - Loft Conversion

naturals

Having just bought a victorian terrace house and with one thing leading to another we need to install some new joists in the attic to take the weight of a cold water tank and a hot water cylinder. We're also looking to have a header tank from a rainwater collection system.

All of this is obviously going to weight a fair bit.

At the minute the ceiling joists are 4x2 at 400 centres spanning around 3.5m (scary or what!). We're looking to convert to attic in the next 12months so I figure I may as well use full size floor joists to strengthen the floor. The problem is that the external loadbearing wall isn't visible in the attic - the rafters / ceiling joists are in an 'A' type arrangement (the rafters bearing the weight of the ceiling joists). Am I ok to fix the new joists through the existing rafters or do I need to invest in some (no doubt expensive) steelwork to take the weight down through the eaves onto the loadbearing wall?

Any thoughts greatly appreciated!

black-saturn

Think you need the advice of a qualified builder not just a few postings on a message board.

naturals

I'm actually a surveyor myself only this isn't a detail I've come across before. I figured someone on here might have experience of it as there must be tens of thousands of Victorian properties which have had lofts converted.

black-saturn

Mines a Victorian Terraced house built in 1897. I tried to get a loft conversion done recently but they said the property wasn't able to have one due to it's age and the strength of the ceilings. However they said I could have this done:

http://www.warmroof.co.uk/

and they gave me a quote for £9,000 to do the whole of the attic.

naturals

That must be one hell of an attic to need £9k of insulation!

We always thought we'd need to beef up the joists to make the attic usable but presumed we'd be able to support them on load bearing walls at each end. The only way I can think of doing it at the minute is to take all the ceilings down and run the joist party wall to party wall. Don't think my partner would approve though...

black-saturn

No that was including putting a floor in, 2 electrical points, a light fitting and a ladder leading to it. So it's a useable room.