joist support

randomi15

Hi Guys,


I have a situation in my house, there is wall using breeze block built on the floorboards !


there is a joist running parallel on either side but nothing to support the wall . It has been like this since 1930s it was built so probably won't collapse. I have removed the floorboard for around 4 month now so literally on the air and it is still fine . I removed it for some piping work




now because the wall is between my bedroom and bathroom, I want to cut floorboard to length so I can lift the floor board needed in future without ripping my bathroom and bedroom out to get the floor board out. this means I will have around 1 floor board meeting on one joist on one side (bathroom), another 1 on another side and finally another 1 between the bedroom and bathroom which will be of small size.


There will then be 20-30 floorboard with same setup of above to cover the whole area of bathroom


see pic below. now my questions is on joist 1 and 2, I will be screwing 4 screws for each floorboard length , does that weaken the wood so much to crack it ? if I do noggin between the joists what will happen ?




I know this can be very confusing so here is a picture and explanation:


yellow- joists
Black , floorboard bathroom side
Red, Floorboard bedroom side
blue, noggins but should I do it as there will be tons of screws left and right on the woods
green, floorboard connecting left and right ( bathroom and bedroom)
purple, where the wall is . it is breeze block
red dots, screws that will go in

casper_g

It's hard to follow the situation, but as I understand it the wall is presently sitting on boards which are supported either side of the wall and continuous over several joists each side. This sounds iffy, but if it's been that way for 80-90 years it probably won't fall down tomorrow.

What you're proposing seems to be to cut the boards on both sides of the wall and leave the wall supported on little bits of board that are supported only by their ends bearing on half the width of a joist each side of the wall. Then you'll weaken the bearing part further by driving two screws through.

In general, I'd say things which have stood up for a long time are unlikely to fall down if left undisturbed, but if you're going to change them fundamentally you should understand what you are doing and be able to justify what you are doing. It sounds like a very poor plan to me.

Perhaps you should would ask a trusted, competent and experienced builder to have a look and comment on the idea of adding noggins to support the wall, as that seems a more reasonable idea to me.

randomi15

thanks for this and you understood it perfectly


wouldn't the wall be still supported by a joist either side relaxing on the green floorboard which is spanning between the joists ?


what I am trying to say is if the green floorboard is not cut and runs across the floor side to side, would that be stronger than it running a shorter distance between the joists and then a red/black floorboard so essentially cutting the single large floorboard to three pieces?




apart from the scenario I have explained, do you generally run floorboard like a puzzle so that all board do not meet on one joist thus creating 4 screws on that joist all across it ?

phill99

Just put a noggin under the green bit.

randomi15

that green bit will span across vertically all the way so we are talking 20-25+ noggings