Sleeper wall query

[Student]

Hi, just rebuilt a suspended floor at my house. Intend to build a sleeper wall mid-span and good job too as there is noticeable flex in the joists at the middle (although that is weighting them individually).

 

It seems that I've either got enough room for a single brick course sleeper with a chunky bit of timber on top, say 3" thick laid on mortar, or two courses with no timber on top or an extremely thin board. 

 

Instinct says go for the first option but is also depends whether the joists should be attached to the sleeper wall or whether they just rest on top of it passively. Would you attach it, if so what method? Fixings through the top of the joists and down into the wall plate or through the side of the joists? And wall plate to wall, are concrete screws down into the brick Ok?

 

P.S. Appreciate there's some odd stuff going on with the design in general - it's a long story!

 

Thanks for any help. 

[Declan52]

Why did you not use 215mm joists as there is another 100mm left to the top of the timber you have bolted to the walls.

 

[Student]

1 hour ago, Declan52 said:

Why did you not use 215mm joists as there is another 100mm left to the top of the timber you have bolted to the walls.

 

It's a bit of an optical illusion, the joists have been installed at a level where there is 40mm between their tops and the floor level in the adjacent room and that's because I've got 40mm worth of floor covering to put on. Unfortunately you can't buy adjustable hangers for 100mm joists because no-one uses 100mm joists on floors but this is a Victorian house and 100mm is actually an upgrade compared to the rest of the ground floor! You can't see because the DPM hides it but the ledger plates are actually sat on brick footings but I've added resin fixings for good measure. Obviously in normal circumstances this arrangement wouldn't work but because it's a kitchen the ledger plate on the RHS will be covered by kitchen cabinets and the ledger plate on the opposite side is below floor level so won't be visible. It's just what I've had to deal with working with what's available on the house, everything is massively out of level. 

 

(This was the long story I was hoping to not have to type out)

Edited July 14, 2019 by Student

[Russell griffiths]

So it’s probably to late for this floor now but there’s a few things not quite right there

now I think this is a kitchen so a few points won’t matter

 

your joist hangers are not right, the full face of the hanger needs to be in full contact with the pole plate bolted to the wall, yours hang below, this helps with deflection. 

 

Your joist length looks a smidge short, this helps with deflection 

 

its a kitchen i know, how would you fit skirting boards. 

 

Off on a tangent, if you intend living there, change the water main, 

 

if there is a brick ledge under that dpc why not have the joists resting on that. 

 

Getting back to your original question, you need a timber under the joists mid span, you will skew nail from the sides of the joists into this wall plate, this helps all the joists act together and helps spread in the centre, none of theses really matter as your span is so small, but it’s nice to do it correctly as it looks right before you cover it up and makes you feel all warm and fuzzy that you did a good job. 

[ProDave]

And can I add, please, before you fit the flooring above, at least fill between the joists with insulation.

[Student]

Thanks for the replies.

 

Do you mean the joint depth looks small? Length wise it's cut pretty spot on I think. 100mm joists is all I could get away with leaving 150mm air gap below. With the sleeper wall deflection will be minimal. In retrospect perhaps I should have sacrificed air gap and put larger joists in. 

 

I did have concerns about the hanger not being fully against the plate but the plate is resting on brick footings, so I couldn't have anything behind the hanger but I could wedge some timber behind if that's worthwhile? The brick footings are too high and not level there's something like 100mm difference over the span of the room. 

 

I have insulation for between the joists and a new water main coiled up and ready to be ran this week but thank you for the recommendations. 

 

Thank you for the information on attaching to the wall plate. How should I attach the wall plate to the sleeper wall? Current plan was to lay it on mortar with dpc below it but wonder if I should put some fixings through into the bricks too?

 

Thanks for all your help. It's a bit of a scrappy job and it pains me not to do it perfectly but I really didn't have much luck regarding depth to work with with the footings being so far out of level, etc. 

[Russell griffiths]

The original one would have just been mounted on a bed of mortar, you may find it a bit clonky if you have any bowed timber as it will lift the plate off of the mortar bed, if this is the case chuck a couple of concrete screws in to the sleeper wall to take the bounce out. 

[Student]

Thanks Russell, I'll do that. 

[Student]

I've got a high spot on my sleeper wall plate where one of the joists will sit on it. What's best to take this out with - a planer? I don't think I own a tool that will do it, so will have to buy something regardless. Something cheap and/or something that can be used a lot for the carpentry that is left on the house (lots of doors/frames and repairs to the stairs to be done). Appreciate any help!

[PeterW]

Saw and chisel. 

[Student]

As I suspected, by attaching the wall plate to the bricks, the bricks are lifting with the wall plate! Argh!

[Russell griffiths]

How on Earth is it lifting the bricks, have you not mortered them down. 

Have you laid them frog down or are they solid. 

I have had this happen but only with old lime mortar that is dry and crusty. 

[Student]

Sorry, I spoke a bit soon on this. It lifted the first brick I did but that particular brick was a bit sparse on mortar but the others were fine (solid engineering bricks). Wall plate seems solid, have chiselled sections that were slightly high. Think this thread is all wrapped-up. Thanks to anyone that helped.