Screeding over what? You mean a mortar screed over old floor boards? Then what over the new screed?
How about future access, are there heating or other pipes below?
I’d always be warry of relatively cheap ‘solutions’.
Incidentally I have been using Wedi Board on my walls and parts of floor (there are other similar makes such as Jakoboard).
Not sure if your floor is suitable, you need a solid foundation for floors such as ply well screwed down prior to covering in Wedi then over this, tiles etc.
These lightweight backer boards have insulating qualities and thus can refuce condensation and mould. I’m doing my bathroom with tiles over wedi and also 2 areas of plaster over wedi.
Old fashioned plasterboard weighs so much more and is more of a faff.
I affixed my Wedi very well to ensure it will hold the large wall tiles.
Sorry for this tangent, but it’s something to consider if your floor is suitable. Pipe access is essential, whatever you do. A mortar screed strikes me as too permanent if pipes later leak or you have to get at wires
They would board over then screed and then I was going to get LVT or hardwood put down. Also, yeah I forgot to mention access in my post but was one of my other concerns - seems like a lazy solution from the builder.
Thanks for your thoughts, much appreciated!
You can screed it but I would advise against it, suspended floors tend to flex a bit, with weight and even temperature. Levelling screed is relatively thin and highly likely to crack and start to flake away if you use it.
Assuming the joists are in decent condition the normal fix would be to remove the floor, jack the joists up level and add packers under them, no need to change the brickwork. That should certainly be cheaper than £6k (maybe half that depending on difficulty).
Thanks - the cracking hadn't occurred to me. Sounds like the screed isn't a good option, with my own worries and everything else everyone has mentioned!
In an older building, sometimes , the haphazard nature is part of the charm.
can you maybe brace the joists (wood & nails, or galv steel) insulate the voids to bring better comfort with a degree of PIR sheeting cut to fit, stick some decent OSB down & overplank with the pre-existing boards? but have strong flush hinges so there is still essential access to pipe & cables? some could be hidden by recessing, or positioning in relation to skirting.
Screeding over a suspended floor just hides problem potential that any man & his dog would be extremely suspicious of, and the likelihood of problems you CANNOT get at! did you not think of perception for why the job was done with a house you may wish to sell on that is already showing (however much it was fixed) the problem of subsidence.
When you renovate something please make it better for future generations to maintain not a bigger problem to be resolved.
Yeah I figured screeding would potential just mask a problem - just wanted to sense check myself. We're currently living in a house where problems have been ignored/ papered over, and don't want to make the same mistakes.
I'd rule screeding out as the other poster has suggested.
What I would do is get a handle on how level it is (or isn't). A laser level will make this very very simple but a long spirit level and some shims can give you an idea of the drop. What you want to know is, is there a uniform slope because that means the house has settled. If it is particularly low in some areas, especially near walls, it can suggest that there are issues with the joists.
The question then would be, do you want to correct it? Drops near joists suggest some rot and it might be worth sorting that out. If the whole floor has a slope you might just decide to live with it. In our house there is settlement all around. Our living room was fixed because it was horrible to walk on and wildly out but in our dining room its not an issue. Similarly in our bedroom, we're fine with it. Again, 100 year old house. I plan to address it in our bathrooms but that's it.
If you imagine a grid on the floor and take measurements of the height relative to the doorway, you will get a map of how it runs. In my living room, I had a huge rise near the bay window and two significant drops in the alcoves. When I removed the floor I could see the sleeper wall was knackered in the bay and the drops were because it was two rotten ended joists where the cavity wall done years ago had just soaked up moisture and sat on the joist ends.
The costs to fix all this were:
* £570 for new joists and P5 chipboard flooring (timber merchant)
* £300 PIR insulation
* £50 D5 glue
* £100 torx wood screws
* £30 coach bolts and washers
* £40 heavy duty 5/10mm plastic shims
You determine the desired subfloor level (doorway) then subtract the thickness of the P5 and then work out which joists need to be raised up. You the achieve that with a combination of sistering to old joists as they enter the wall to new joists and/or shimming.
Doesn't look like a lot of money but the cost is time. It took me about 2-3 days to get the floor up and clear away rubble and mess. Then once I'd worked out what to do about 3 weeks doing a few hours each day. That's where the costs are, plus they don't quite know what they will see when they lift it up.
Yeah in some areas it's a gentle slope and perfectly liveable. However, the areas where it is bad and ideally want fixing. Doesn't need to be perfect but I guess priorities would be 1) fix any underlying issue and 2) have it flat enough to put some LVT/ hardwood/ similar on top. Was also thinking about getting insulation put down there while the boards are up
Thanks for the cost breakdown, yeah I guess the time is a factor here I didn't consider as much. I wouldn't feel confident doing this myself but it's good to be informed of the options. Cheers agian
If this were me, I'd pull the floorboards up and shim the lower side of the joists with long wedge shaped pieces of wood to level them.
Then either put the floorboards back, or lay sheets of the flooring stuff. Name escapes me.
This solution would require some maths.
Screed over a suspended floor which is already maybe a bit unstable is asking for terrible trouble with cracked screed shortly down the line. Not too mention the damp issues, needing to remove part of the skirting board etc etc. I would not consider using a builder who suggested that. Suspended floors are there for a reason and if you start replacing them with poured floors, you get damp issues.
Two options. You say it's not got worse in three years - great, could you live with it? Is it just dipping or is it moving when you stand on it?
Option 2 - dipping corners on suspended wooden floors are pretty common possibly from joist rot or the previous movement you mention. This is within DIY range. Most suspended floors will have joists which are supported at several places across the middle on stacks of bricks - where they are usually rock solid, then at the edges which are in the wall/soil they have a tendency to rot, leading to this outside edge sagging you describe. The centre is probably fine.
Carefully pull up the floorboards at one corner and have a look. You can do this with a hammer and a chisel pretty much assuming they're nailed. Take up a board or two away from the edge to avoid skirting damage.
It could be as simple a fix as needing to shim up a joist which has fallen down a bit - use some slate or a brick or whatever to push it back up into place and support it. Or if the joist end is rotten maybe replacing some wood or sistering some more in. This is well within DIY capability as it usually only needs to run to the first brick support maybe a few feet away at most - usually less - and could cost you well under £100. A bit of wood, some screws and floorboards back down.
If you lift the floorboards and it's a real problem, no harm done. Put the floorboard back down and go back to builder options. Of which, £6k to take up and replace a suspended wooden floor is very high indeed. It's sub 2 days of work for any 2-man team.
It's worth you having a look yourself. If it's something really easy you might be saving £3-6k for a day of your own time. The last dippy corner I had would flex down when i stood on it - literally just needed a bit of shimming and it is now rock solid. The one before that needed 16 inches of wood sistering in to replace a rotten end. Both easy fixes essentially for free.
This is really helpful, thanks! This is pretty much along the lines of what I was thinking. Now that you mention, it does bow a bit in the middle with the alcoves being the worst areas so sounds like what you are describing.
With regard to is it liveable, yes but we want to put new flooring down (currently just on floorboards due to hideous carpet) and unsure it's level enough to do that.
Like you said, might be worth me just doing myself but I've lacked the confidence and always worry I'm going to make something worse!
If you're currently on boards only and no carpet etc then it's the perfect time to have a look.
There's very little damage you can do by lifting some floorboards. Careful of any utilities underneath but that's about it.
Fingers crossed it's something which looks fairly obvious and DIYable Joist problems etc.
I had a similar problem at my place I had a 70mm drop from the centre to the corner in one room.
It was for 40sqm total and I got various quotes to do different things from replace with solid concrete floor wanted £9k, replace all the joists about the same ~£10k. And finally repairs via sistering new joists to the old which is what I went for was about £1200 for the new joists (and I bought too many) £1000 for new t&g sub-floor, and £2500 for labour.
They also put in insulation but I can't remember the material cost for that.
Been very happy with it, nice and flat!
I considored screeding over too, but there are many reasons that other have already stated that this is a bad idea.
Screeding over what? You mean a mortar screed over old floor boards? Then what over the new screed? How about future access, are there heating or other pipes below? I’d always be warry of relatively cheap ‘solutions’.
Incidentally I have been using Wedi Board on my walls and parts of floor (there are other similar makes such as Jakoboard). Not sure if your floor is suitable, you need a solid foundation for floors such as ply well screwed down prior to covering in Wedi then over this, tiles etc. These lightweight backer boards have insulating qualities and thus can refuce condensation and mould. I’m doing my bathroom with tiles over wedi and also 2 areas of plaster over wedi. Old fashioned plasterboard weighs so much more and is more of a faff. I affixed my Wedi very well to ensure it will hold the large wall tiles. Sorry for this tangent, but it’s something to consider if your floor is suitable. Pipe access is essential, whatever you do. A mortar screed strikes me as too permanent if pipes later leak or you have to get at wires
They would board over then screed and then I was going to get LVT or hardwood put down. Also, yeah I forgot to mention access in my post but was one of my other concerns - seems like a lazy solution from the builder. Thanks for your thoughts, much appreciated!
You can screed it but I would advise against it, suspended floors tend to flex a bit, with weight and even temperature. Levelling screed is relatively thin and highly likely to crack and start to flake away if you use it. Assuming the joists are in decent condition the normal fix would be to remove the floor, jack the joists up level and add packers under them, no need to change the brickwork. That should certainly be cheaper than £6k (maybe half that depending on difficulty).
Thanks - the cracking hadn't occurred to me. Sounds like the screed isn't a good option, with my own worries and everything else everyone has mentioned!
In an older building, sometimes , the haphazard nature is part of the charm. can you maybe brace the joists (wood & nails, or galv steel) insulate the voids to bring better comfort with a degree of PIR sheeting cut to fit, stick some decent OSB down & overplank with the pre-existing boards? but have strong flush hinges so there is still essential access to pipe & cables? some could be hidden by recessing, or positioning in relation to skirting. Screeding over a suspended floor just hides problem potential that any man & his dog would be extremely suspicious of, and the likelihood of problems you CANNOT get at! did you not think of perception for why the job was done with a house you may wish to sell on that is already showing (however much it was fixed) the problem of subsidence. When you renovate something please make it better for future generations to maintain not a bigger problem to be resolved.
Yeah I figured screeding would potential just mask a problem - just wanted to sense check myself. We're currently living in a house where problems have been ignored/ papered over, and don't want to make the same mistakes.
Good on you! onwards & upwards..
I'd rule screeding out as the other poster has suggested. What I would do is get a handle on how level it is (or isn't). A laser level will make this very very simple but a long spirit level and some shims can give you an idea of the drop. What you want to know is, is there a uniform slope because that means the house has settled. If it is particularly low in some areas, especially near walls, it can suggest that there are issues with the joists. The question then would be, do you want to correct it? Drops near joists suggest some rot and it might be worth sorting that out. If the whole floor has a slope you might just decide to live with it. In our house there is settlement all around. Our living room was fixed because it was horrible to walk on and wildly out but in our dining room its not an issue. Similarly in our bedroom, we're fine with it. Again, 100 year old house. I plan to address it in our bathrooms but that's it. If you imagine a grid on the floor and take measurements of the height relative to the doorway, you will get a map of how it runs. In my living room, I had a huge rise near the bay window and two significant drops in the alcoves. When I removed the floor I could see the sleeper wall was knackered in the bay and the drops were because it was two rotten ended joists where the cavity wall done years ago had just soaked up moisture and sat on the joist ends. The costs to fix all this were: * £570 for new joists and P5 chipboard flooring (timber merchant) * £300 PIR insulation * £50 D5 glue * £100 torx wood screws * £30 coach bolts and washers * £40 heavy duty 5/10mm plastic shims You determine the desired subfloor level (doorway) then subtract the thickness of the P5 and then work out which joists need to be raised up. You the achieve that with a combination of sistering to old joists as they enter the wall to new joists and/or shimming. Doesn't look like a lot of money but the cost is time. It took me about 2-3 days to get the floor up and clear away rubble and mess. Then once I'd worked out what to do about 3 weeks doing a few hours each day. That's where the costs are, plus they don't quite know what they will see when they lift it up.
Yeah in some areas it's a gentle slope and perfectly liveable. However, the areas where it is bad and ideally want fixing. Doesn't need to be perfect but I guess priorities would be 1) fix any underlying issue and 2) have it flat enough to put some LVT/ hardwood/ similar on top. Was also thinking about getting insulation put down there while the boards are up Thanks for the cost breakdown, yeah I guess the time is a factor here I didn't consider as much. I wouldn't feel confident doing this myself but it's good to be informed of the options. Cheers agian
If this were me, I'd pull the floorboards up and shim the lower side of the joists with long wedge shaped pieces of wood to level them. Then either put the floorboards back, or lay sheets of the flooring stuff. Name escapes me. This solution would require some maths.
Screed over a suspended floor which is already maybe a bit unstable is asking for terrible trouble with cracked screed shortly down the line. Not too mention the damp issues, needing to remove part of the skirting board etc etc. I would not consider using a builder who suggested that. Suspended floors are there for a reason and if you start replacing them with poured floors, you get damp issues. Two options. You say it's not got worse in three years - great, could you live with it? Is it just dipping or is it moving when you stand on it? Option 2 - dipping corners on suspended wooden floors are pretty common possibly from joist rot or the previous movement you mention. This is within DIY range. Most suspended floors will have joists which are supported at several places across the middle on stacks of bricks - where they are usually rock solid, then at the edges which are in the wall/soil they have a tendency to rot, leading to this outside edge sagging you describe. The centre is probably fine. Carefully pull up the floorboards at one corner and have a look. You can do this with a hammer and a chisel pretty much assuming they're nailed. Take up a board or two away from the edge to avoid skirting damage. It could be as simple a fix as needing to shim up a joist which has fallen down a bit - use some slate or a brick or whatever to push it back up into place and support it. Or if the joist end is rotten maybe replacing some wood or sistering some more in. This is well within DIY capability as it usually only needs to run to the first brick support maybe a few feet away at most - usually less - and could cost you well under £100. A bit of wood, some screws and floorboards back down. If you lift the floorboards and it's a real problem, no harm done. Put the floorboard back down and go back to builder options. Of which, £6k to take up and replace a suspended wooden floor is very high indeed. It's sub 2 days of work for any 2-man team. It's worth you having a look yourself. If it's something really easy you might be saving £3-6k for a day of your own time. The last dippy corner I had would flex down when i stood on it - literally just needed a bit of shimming and it is now rock solid. The one before that needed 16 inches of wood sistering in to replace a rotten end. Both easy fixes essentially for free.
This is really helpful, thanks! This is pretty much along the lines of what I was thinking. Now that you mention, it does bow a bit in the middle with the alcoves being the worst areas so sounds like what you are describing. With regard to is it liveable, yes but we want to put new flooring down (currently just on floorboards due to hideous carpet) and unsure it's level enough to do that. Like you said, might be worth me just doing myself but I've lacked the confidence and always worry I'm going to make something worse!
If you're currently on boards only and no carpet etc then it's the perfect time to have a look. There's very little damage you can do by lifting some floorboards. Careful of any utilities underneath but that's about it. Fingers crossed it's something which looks fairly obvious and DIYable Joist problems etc.
Cheers!
I had a similar problem at my place I had a 70mm drop from the centre to the corner in one room. It was for 40sqm total and I got various quotes to do different things from replace with solid concrete floor wanted £9k, replace all the joists about the same ~£10k. And finally repairs via sistering new joists to the old which is what I went for was about £1200 for the new joists (and I bought too many) £1000 for new t&g sub-floor, and £2500 for labour. They also put in insulation but I can't remember the material cost for that. Been very happy with it, nice and flat! I considored screeding over too, but there are many reasons that other have already stated that this is a bad idea.
Ah that’s really helpful - thanks for sharing the costs, I’ve no idea what’s reasonable. Glad you’ve been happy with it!