Block Partition Wall Upstairs!!

wall, since they can even fuss about this for a stud wall. Interesting though, since with blocks the whole thing is perhaps tied together more due to the mortar etc. I have upstairs walls in my house that are cinder blocks over floorboards, at right angles to the joists, but they are a short distance from the brick partitions downstairs. The only exception is a brick spine wall up the middle of the house that also helps to support the roof purlins via a V-shaped arrangement. I hope this spine wall will be able to support a structural floor in the loft in the future, avoiding the need to big steels. Simon.

No it's not uncommon. The floor joists should be strong enough and stiff enough to support the wall. The joists will deflect as the partition is being built so then the only deflection after the mortar has set will be down to the usual occupancy loads.

na, it happens often enough. Best obviously when running perpendicular to the joists! (can be done parallel if you double up the joist instead). Having said that you often see places where it is parallel to the joists and not even over them - sat on the floor between a pair of joists.

One thing this makes you think about - how much of a house is based on wood - even a block-built house. In a bad fire, tons of block built on upstairs rafters could come crashing down, causing far more danger than with stud walls. I remember someone saying that an American they knew was scared of our brick houses "in case it collapses on top of me". I guess they came from a earthquake zone ! Simon.

My bathroom wall is made this way. It's a bit of a pain since some of the floorboards need replacing!

Just don't do them all at once! ;-)

In a fire, timber joists are a far better bet than steel beams, and the joists are protected by a plaster[board] ceiling.

On Fri, 04 May 2007 12:26:33 GMT, a particular chimpanzee, Tony Bryer randomly hit the keyboard and produced:

Except when the joists are TJI joists, and except when the plasterboard ceiling has holes dotted in it for downlighters! Like a small (show) house fire recently that burnt through the webs of the joists, leaving the floor deflected by about 200mm and completely unsupported. If it had been occupied, it's probable anyone up there, including firefighters, would have come through the floor.

What I find more than a little worrying is the thought of this situation occurring when the floor separates two flats. If you are in the upper flat your safety may be fatally compromised without you realising it.

On Sun, 06 May 2007 13:15:31 GMT, Tony Bryer mused:

The floors between 2 flats should be of a better fire resistant construction than between 2 levels in a domestic multi storey property though.

On Sun, 06 May 2007 21:24:54 GMT, Tony Bryer mused:

Nowadays fire hoods should be fitted and all fire breaks should be maintained through walls and ceilings. Most ignore that though.

I'm not up to date with current requirements, but it used to be full 1/2 hour for 2-storey (2 layers PB) and one hour for 3-storey which IIRC was 2 x 12mm PB. No protection against holesaw man and his concealed downlighters.