RSJ to support roof wall plate?

[DIYedboy]

I'm thinking of putting a 2 storey extension (flat roof) on the rear of my 1930's solid wall semi (no skeilings). the idea is to make the existing two upstairs bedrooms bigger by 5ft (knock out old rear wall).

Will I need nasty old heavy RSJ's to support the roof wall plate? or will I get away with lovely old 9x2's bolted together seeing as we aren't supporting any silly old brickwork?

 

[garyo]

In a very similar situation I was asked to use an RSJ instead of two sistered beams, but only a little-un at 80mm x 120mm. I was on a 4.6 metre span.

It worked well in the end - I bolted a piece of timber between flanges and then used joist hangars, so you can't tell there's any RSJ at all - there's no step-down in the ceilings.

Gary

 

[DIYedboy]

Jeez Gary, it's the thought of all that heavy humping upstairs that's putting me off

 

[tony1851]

You can use timber beams to support the old wall plate, but it depends on the span as to how deep the beam would be.

btw, would you get planning permission for a two-storey extension with a flat roof?

 

[DIYedboy]

I have no idea Tone, the increase in room size would be 5feet by the width of the house (a12 foot and an 8 foot room), originally I was only going to do downstairs, but then I thought, it's not much more effort to carry the blocks up another storey and then you've got great bedrooms too!

 

[garyo]

More faff without a doubt. In the end I was pleased though - the lower profile meant I could hide it in the ceiling without it causing me problems with the roof line.

Managed to man handle it up with a mate - only cost me a beer!