Flitch beam for future second storey

[burts]

I have a ground floor rear extension waiting for a flat roof to go on. Decided to possibly plan for future timber frame second storey or if I can add to plans now. Rear extension 7.3m long by 4.3m wide. Second storey to be same width by 3m long. SE has designed a flitched beam for where end wall would go up. If prepping for future, should I put a joist in either side,board up to the flitch beam and put a separate piece of board over flitch beam so it can come up Without needing to much restructure ?
Also would I build off the beam with upright timbers or do I screw another floor plate on to the top of it. Not sure if any of this makes sense

 

[tony1851]

Why use a flitched beam in the first place? A steel beam with a timber plate bolted to the top flange would have been fine
and probably cheaper.

 

[burts]

Why use a flitched beam in the first place? A steel beam with a timber plate bolted to the top flange would have been fine
and probably cheaper.

Because the second storey is a new idea after the extension has been built. So Blocks on the inner leaf with wall plates already on . So I could use steel but would I have to cut the plates and some of the block to get an engineering brick in place to support the beam. How can I steel beam be cheaper than 3 joists with 2 6mm plates bolted in between them. I’ve no experience of them

 

[tony1851]

Because the second storey is a new idea after the extension has been built. So Blocks on the inner leaf with wall plates already on . So I could use steel but would I have to cut the plates and some of the block to get an engineering brick in place to support the beam. How can I steel beam be cheaper than 3 joists with 2 6mm plates bolted in between them. I’ve no experience of them

If your second storey is going to be timber framed, you do not need to cut the wall plate to put any padstone or engineering brick on the blockwork.
The loading from a timber frame is very low, so a steel beam could bear directly on the wall plate. If it is a wide-flange beam -say one of the 152 x 152 beams, there would almost certainly be enough bearing area for the timber not to be overstressed in compression; if it was a narrower beam, a 12mm steel bearing plate would suffice.
We have done this many times on loft conversions where a steel beam bears directly on a wall plate, to avoid disruption to the room below by putting in a padstone. It's just a 5 minute job to do the number crunching to check; nine times out of ten it can be shown to work.

 

[Notch7]

Because the second storey is a new idea after the extension has been built. So Blocks on the inner leaf with wall plates already on . So I could use steel but would I have to cut the plates and some of the block to get an engineering brick in place to support the beam. How can I steel beam be cheaper than 3 joists with 2 6mm plates bolted in between them. I’ve no experience of them

Prob not much diff in price.

Drilling and bolting a flitch beam is quite time consuming -a universal beam / column is off the shelf, no extra sitework.

 

[burts]

If your second storey is going to be timber framed, you do not need to cut the wall plate to put any padstone or engineering brick on the blockwork.
The loading from a timber frame is very low, so a steel beam could bear directly on the wall plate. If it is a wide-flange beam -say one of the 152 x 152 beams, there would almost certainly be enough bearing area for the timber not to be overstressed in compression; if it was a narrower beam, a 12mm steel bearing plate would suffice.
We have done this many times on loft conversions where a steel beam bears directly on a wall plate, to avoid disruption to the room below by putting in a padstone. It's just a 5 minute job to do the number crunching to check; nine times out of ten it can be shown to work.

Thanks for this. I had to have piles and ground beams etc so everything has gone through an SE and he is the one who has stated that flitch beam straight on wall plate or steel beam on to engineering block. So although I’m thankful for your knowledge that’s what he’s put so that’s what I’m governed by unless BC allow otherwise. I will get them out once the other joists are in place and see what they say. The beam was 203 x 133 UB25. This was when joists were 200 x 50 but I need to upsize to 245 x 47 to match existing floor level. Just want to have it all in place so next summer I can cut the flat roof, remove top deck and insulation and hey presto I have a floor already down and a beam to build off. Another question springs to mind, when I do this, can I build my wall plates for 1st floor straight off the deck that will be down if I mark the beam/steel or will I have to expose back to beam and wall plate on flank walls

 

[burts]

Prob not much diff in price.

Drilling and bolting a flitch beam is quite time consuming -a universal beam / column is off the shelf, no extra sitework.

Yeah I hear you and time is always the one thing we don’t have! If BC say I can lay it on wall plates and block wall then I will.

 

[burts]

So I went with the flitch beam. Two plates with Pre drilled holes £160 cash plus £60 joists and whatever the bolts will cost.

Questions regarding joists. They’ve turnt up and I don’t think treated. Is this a problem? Can I cut my joists flush to wall if I want tight fascia? ( it where gutter is) and a chippy is saying use a nail gun to fix, I was planning on angled brackets with 30mm nails and an estwing hammer ??