Insulating under timber floor, how to get behind sleeper wall

Good afternoon,

Im looking to insulate my suspended timber flooring (ground floor) the crawl space under the house is around 70cms, which I've been around and am happy to work under. Im planning on using king span between the joists. I can fit in crawl space all around the house expect where the bay window begins. I believe there is a sleeper wall blocking me from reaching the area next to the window.

this photo Is from my video crawling under the house, the wall has lots of gaps in it, which from searching looks like sleeper?


this is the plan of the living room


Would I be able to knock a crawl hole out of that sleeper wall? possibly put some timber onto of the sleeper?
if is this is possible would I need a jack to hold above the sleeper before I knock it out and put the timber in?
what size timber would be recommended?

Thankyou for any advice

AjWill said:

Would I be able to knock a crawl hole out of that sleeper wall?

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No.

Why can't you do the work from above?

I didnt want to rip the living room floor boards out and cause any disruptions if possible. Im not confident in ripping up the floor boards without damaging them, they are sanded and polished as a feature for the living room. I was hoping I could do it all from underneath. im guessing having all the room insulated excluding next to the window would have a rather large detriment to the performance too...

is there anything else I could do?

Thanks

AjWill said:

I didnt want to rip the living room floor boards out and cause any disruptions if possible. Im not confident in ripping up the floor boards without damaging them, they are sanded and polished as a feature for the living room. I was hoping I could do it all from underneath. im guessing having all the room insulated excluding next to the window would have a rather large detriment to the performance too...

is there anything else I could do?

Thanks

Click to expand...

I believe if you were to remove any of the sleeper brickwork it would have to be replaced with a supporting lintel as it's a supporting structure but looking at the state of the brickwork it could be quite a pain. I'd sooner take the floor up - it'll be more detremental to interfere with the supporting brickwork than it would to worry about a bit of polished flooring.

Thank you for the advice ill have a look at possibly removing the floor in just that area, see how difficult it will be.

AjWill, good evening.

I am with you on not wanting to rip up a possibly Old sanded polished timber floor, yes you can do it BUT??? the resultant "Patch" will be visible forevermore

From the images you posted it appears that the sleeper wall aint supporting all that much??

I would go for removing the smallest area of brick as possible to get you and the material through, not necessarily at the same time??

Proviso is that you will need to plan ahead a bit in that you will need to form your access hole between the floor joists above, I assume the joists run front to rear?

You should also consider fitting a lintel of some sort, concrete or even treated timber to bridge the gap and afford some stability between the areas of the dwarf wall remaining

Suggest you choose the widest span between the joists to form the crawl hole in, but keep the crawl space as small as practicable.

As an aside when you are down there suggest you ensure you clear the inside of the air bricks to ensure there is a good amount of ventilation unimpeded under the floor.

If you have any concerns about the stability of the dwarf wall oncw you have completed the insulation install, you could re-construct the wall?

Ken

Thanks Ken,

I don't think the wall does support much either. im planning to go back under and get some better photos at the weekend. Joists run front to rear yes.

Something like this as a lintel may suffice? https://www.diy.com/departments/exp...oncrete-lintel-l-1050mm-w-100mm/150790_BQ.prd

so if all the joists are say 70cm apart, just make a hole in-between the joists that I can hopefully fit through, then put the lintel up and cement the lintel in?
and then be as delicate as possible removing the bricks and re insert half bricks?

there is already two or three holes with lintels to crawl through reaching the living room, I can hopefully just mimic one of those to get to the end?

Thanks again
Alex

AjWill said:

I don't think the wall does support much either. im planning to go back under and get some better photos at the weekend. Joists run front to rear yes.

Click to expand...

And if doesn't strike you that's what it's supporting?

I see your point. weight wise it shouldn't be too much of an issue to remove some bricks between the joists insert a lintel put some half bricks back in, along as there is nothing above the floor at the time?

ok so I went back under and got a good look with some photos, the gap behind the sleeper wall only seems to be 30cms at its deepest, so I was thinking I could just push the insulation along the gap up to the wall, it will sag a bit tad at the end, but maybe theres a tool, or a method I dont know of that will allow me to put something in at a reach to butt it up the to boards?

Assuming you are going to use Kingspan, or another rigid insulation board, you could make the board significantly longer than the depth to the wall, slide it in and lever it up to touch the underside of the floorboard along it's length, then add a bracket or spacer at the sleeper wall to hold it there.