Sorting an uneven concrete floor

[MikeG.]

Actually, no, I'm seeing that as good news. It confirms that you have to deal with that floor properly. It has to come out (it doesn't look like it will put up a lot of resistance), and a new one poured over a DPM. Hire or borrow a Kango, start at an edge and nibble off small chunks, and that floor will take half a day I reckon. You really don't have to do this until summer, when you'll be able to empty the workshop and store stuff safely under tarps etc if necessary.

I'm always glad when the answer is obvious, because then you know that what you are proposing to do will actually fix the problem. Nothing worse than "let's give this a go" and then finding that it makes no difference. Here, it isn't the only issue to be dealt with, but if you fixed everything else and left this floor, you would still have a damp workshop.

 

[SammyQ]

Hi Paul. At the risk of being seen as sycophantic, I totally agree with MikeG; floor has to come out, both as a fix for it's own problem AND as a basis for a little more work on the walls.
I also agree that the floor looks shot and a half-decent Kango will chew it up pronto, maybe 2 hours. I found a pickaxe handy to prize it up in larger slabs (easier to move to the skip*) when I did my excavation work and my five foot crowbar ( now in its third family generation) was perfect tool too. Rugged gloves are an absolute requirement, as the riven edges of the concrete fragments are like razors. You COULD think of breaking up the old slab in situ as hardcore for the new pour, but I suspect you may have to dig down min 6" and then install a new DPM - on sand blinding - before chucking some 'muck' on and levelling to floor level. Mike, or any competent builder, please correct and/or contradict a weekend warrior's witterings in this respect. The nice thing is, once you put in two days work, the new floor will make everything better, and you remove heartache and frustration as your tools and projects suffer from damp and its camp followers, rust and mould.
Sam, with memories of doing a whole kitchen like this...
* Larger slabs mean more material per lift, less farting about with a shovel; far less 'housekeeping' to prepare for new pour. Just mind your back, get a helper.

 

[LarryS.]

Thank you both, sounds like my only option is fairly big works....

Dig out path on left, bamboo on right, ground at back, and then the floor of the garage, then

re-lay floor with a DPM, put in a drain at front and a soak way for it (current downpipe just drains into a gravel siding to the drive), build a new lower path on left (we need that access). So much for hoping this would be easy but I’m happy that this is a full and proper solution.
If there are any shortcuts which would result in a viable solution then please shout!

Thanks again


Paul




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[SammyQ]

Sorry Paul, but you have to get the basics right make future work viable. If it is any comfort at all, in the last three months I have had to, :
1)Install a new gas boiler
2) install a full loft of insulation
3) Employ a drainsman with a camera and a 4000 psi lance
4) Employ a builder to stop rising damp
5) Take on a professional rodent exterminator
6) Remove a substantial amount of concrete and half a tonne of soil, causing underfloor damp.
7) Remove and then replaster behind, a built in wardrobe, as the mould in it rotted boots and coats.

This is not my garage, it's my (new-to-me) home!! And, we're not done yet! The builder is coming back tomorrow to install air vents below the damp course to help dry out a sopping underfloor.

Want to know WHY all this is going down?? Because, just like your garage builder, a builder serving two-owners-before-me was CARP at his job and left behind horrors. The elderly couple before me just threw spondulicks at the problems, didn't investigate, didn't rectify. POLTROONS!! I feel for you Paul. I have already done a similar job over a number of years, to my previous place in Belfast, while raising three kids. It ain't easy, or quick, but it is wholly satisfying to make things better.

Hang in there Spud.

Sam

 

[LarryS.]

All understood Sam and as ever i'll get it done, recent experience though with the 3 kids and the puppy was I was asked to hang a picture up, it took 3 days to find the time !




Paul

 

[SammyQ]

=D> =D> =D>

Sam

 

[autotrans]

(hammer) (homer)

 

[LarryS.]

Ok so as predicted with 3 children it’s taken time to get going but as of now we have an extension being built on the house , and whilst we’re at it I’m getting the garage sorted

Pictures attached but so far
1. Path on the left has been dug down to 2 courses below dpc
2. Garage is mostly emptied (will finish tonight)
3. I’ve got a breaker ready to take the floor up
4. A new floor and dpm will be installed Friday

Supplementary question I’m hoping someone can help with. The floor to rafters height is only 230cms, rafters to underside of the ridge beam is 1m, so I’d like to take each rafters out one at a time, shorten it, and raise it 30cms before reattaching with m10 bolts. Does that sound like the right way to do it ? I’ve done a lot of internet research but most answers come back with an American accent, and I’m not sure they have the same approach as if need here

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[LarryS.]

Oh, and I’ve got a 10mm armoured cable run up underground and into the garage, very excited for that upgrade compared to the 2.5mm cable that was previously swinging from a catenary wire


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[beech1948]

Paulr,

I was catching up on your progress by accident and thinking about the RHS of the garage where the bamboo or whatever is coming through. A simple and cheap solution is to put down a layer of salt ie. typical domestic salt. Cover the whole part between the boundary and garage and lay it on thickly. The bamboo/eucalyptus will start to die very quickly.

Al

 

[LarryS.]

Al

If that works then that is a great idea, I’ve been putting off that part of the work til last

More progress today, floor dug out is high as predicted was full of rubble, I’m beat

Can anyone give me feedback on raising the rafters as I’ll be doing it in the next few days hopefully
Cheers

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[Sheptonphil]

Can anyone give me feedback on raising the rafters as I’ll be doing it in the next few days hopefully
Cheers
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Excellent work digging out that lot.

Why are you raising the rafters? Looks like you have loads of headroom already. Just curious.

 

[beech1948]

Re your rafters.

I think the rafters are the ones which rise from the sole plate to the ridge. What you call a rafter is properly called a tie beam. Its job is to prevent the rafters spreading and causing the walls to bow outwards from the weight of tiles on the roof.

If you want to remove one and then shorten it and raise it up say 300 mm or so then you are OK to proceed. Removing one will not cause any issues with your roof. Replacing it say 20 mins later but 300 mm or so higher will not cause any problems. You should consider maybe fastening the rafter to the brick with a 18" length of what I know as "builders band" a galvanised steel band say 1" to 2" wide which can be twisted into the shape you need and screwed into wood or brick using trad fixings. Problems can occur if you try to go too high with the tie beam but you mentioned that you were looking for a smallish increment in height available.

Al

 

[LarryS.]

Can anyone give me feedback on raising the rafters as I’ll be doing it in the next few days hopefully
Cheers
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Excellent work digging out that lot.

Why are you raising the rafters? Looks like you have loads of headroom already. Just curious.

As Al has pointed out i got the terminology wrong, its the tie beams I want to raise, and it's because their height at the moment is 230cms but i want to be able to handle 240cm sheets, so a 20/30 cms rise should sort it

 

[LarryS.]

Re your rafters.

I think the rafters are the ones which rise from the sole plate to the ridge. What you call a rafter is properly called a tie beam. Its job is to prevent the rafters spreading and causing the walls to bow outwards from the weight of tiles on the roof.

If you want to remove one and then shorten it and raise it up say 300 mm or so then you are OK to proceed. Removing one will not cause any issues with your roof. Replacing it say 20 mins later but 300 mm or so higher will not cause any problems. You should consider maybe fastening the rafter to the brick with a 18" length of what I know as "builders band" a galvanised steel band say 1" to 2" wide which can be twisted into the shape you need and screwed into wood or brick using trad fixings. Problems can occur if you try to go too high with the tie beam but you mentioned that you were looking for a smallish increment in height available.

Al

thanks Al you were right on my incorrect terminology. What is the purpose of the builders band strapping for the rafters?

And Phil - the dig out was tortuous, especially on such a muggy day, but it's done now and i'm guaranteed to sleep deeply tonight

paul

 

[beech1948]

Paulr,

When/if you raise the tie beams by say 300mm then I expect the rafters to be secured to the sole plate by a birds mouth cut out in the rafter end to fit to the sole plate. This would/should have at least 2 or more nails through the rafter end into the sole plate. I was just thinking that its not a lot to hold the weight of the roof over any single rafter and a bit of extra security might be handy. It would hold the rafter down onto the sole plate because it would be secured into the wall below thus pulling the roof down onto the load bearing surface.

I'm always over building and believe belt and braces is probably the best policy. Perhaps overly cautious.

 

[beech1948]

Lets see last post was August....any updates. ?