Over floor pour

[cityhick]

Has anyone here or know of anyone else or another thread that could give me some info. Heres the deal, my garage is 22x22 the floor is in bad shape and I have kicked aroung several ideas of the best possible route for MY situation. Long story short is tearing the garage down and building new is not possible. I think...think....that I am going to rail up the inside of the walls and pour a six inch slab with fiber and wire over the top of the existing floor and then raise the ceiling joist up so that I can put in an eight ft tall door.......Any help/thoughts/ridicule/ideas or anything else you could think of is welcome...............Thanks,Mike

 

[camarotoolman]

Sounds good to me, just set 2x12s on your top plate?

 

[OccupantRJ]

Are you talking about raising the entire roof, or just a section of the ceiling joists? Do you actually have joists and rafters, or do you have roof trusses?

 

[ptschram]

I'm not sure that I'd want to pour the new slab over the existing one.

Were it me, I'd think about removing the current floor and pouring a new floor.

 

[djkeev]

Hmmm, from decades of experience, pouring a new floor over a weak cracked poorly installed slab is a really really bad idea. Problem is that cars are heavy, you need a solid base to support the concrete, without the base the weight forces the slab down and any movement will cause a crack, a crack becomes two cracks then three and four and five.......
Remove the old floor, dig down and lower your floor to give you your height and put in a proper base, quick easy effective, regrade your driveway to the new floor. Lacking the ability to go down at least remove the unstable old floor!

Dave
Sent from my iPhone 4s

 

[ambenz]

I think it's a plan that you can do while laying out small chunks of change that won't hurt your pocket book and it will also forgo any interest payments....but will possibly cost just as much in the long run and you'll end up compormising on what you could dream of as the perfect garage.
My neighbor is in the same boat as you are and is thinking the same thing. That big cash outlay or refinancing the mortgage to get the cash for a new garage is really worth the effort if it's feasible.
I would jack up the garage, jackhammer the slab, pour a true foundation, and then pour a new slab. Shore up the existing building and add short sides from the new foundation to the existing garage. Hope those old timbers and sills are not punky! Resquaring the existing structure is tricky too.
The is a thread that someone did exactly what you are planning here, somewhere...I'll try to find it....good luck!

 

[ConCretin]

Hmmm, from decades of experience, pouring a new floor over a weak cracked poorly installed slab is a really really bad idea. Problem is that cars are heavy, you need a solid base to support the concrete, without the base the weight forces the slab down and any movement will cause a crack, a crack becomes two cracks then three and four and five.......
Remove the old floor, dig down and lower your floor to give you your height and put in a proper base, quick easy effective, regrade your driveway to the new floor. Lacking the ability to go down at least remove the unstable old floor!

This! Remove the old floor first and make sure you have a decent base before placing a new one. Waste of time and money otherwise.

 

[bczygan]

Whatever conditions that caused the existing floor to degrade, still exist and will continue to move and crack the existing floor. That will telegraph through and crack and destroy the new floor slab.
You need to completely remove the existing slab.
You need to determine the condition of the foundation walls and if necessary repair or replace them or install proper ones if none exist.
You then need to remedy the conditions that caused the existing slab to crack.
This means removing the existing base materials and installing a new base, properly compacted. This should be installed until it is above surrounding grade for positive drainage.
Drainage needs to be installed as required to keep the base dry. Use gutters and downspouts with kick outs to keep water away from the foundation.
After all these things are completed you can place a new slab.
Any other method is a waste of time and money.

 

[mitusa]

Only thing I would add.......sometimes over the years, the yard around houses and garages eventually become "higher" than the house and garage. I've had to take a tractor and blade and scrape the yard down to keep runoff from going to the house foundation, garage foundation. You don't want rain water to go towards your house or garage. If this is a problem, you need to fix it. Water around your foundation or under your slab will only accelerate the problems you seem to be addressing now.

Good luck!

 

[tcianci]

Once again, the armchair engineers have got multiple scenarios going that have no basis in what the OP was asking. To the OP:
If you have a conventionally framed (stick framed) roof rafter assembly, yes, you can raise the ceiling joists to allow for a higher door. The best way to do this would be to cut out every other ceiling joist, shorten it and re-install it at the new height. Then, go back and raise the rest of the ceiling joists. this will save the cost of buying new wood and aso keep the building stable through the ceiling raising process. Make sure to construct a similar header to what you currently have when you raise the height of the door opening. It would be helpful to see how your building foundation and floor are currently constructed before anyone can make an educated comment on what to do there, although pouring over a deteriorated slab is seldom a good idea.

 

[cityhick]

Once again, the armchair engineers have got multiple scenarios going that have no basis in what the OP was asking. To the OP:
If you have a conventionally framed (stick framed) roof rafter assembly, yes, you can raise the ceiling joists to allow for a higher door. The best way to do this would be to cut out every other ceiling joist, shorten it and re-install it at the new height. Then, go back and raise the rest of the ceiling joists. this will save the cost of buying new wood and aso keep the building stable through the ceiling raising process. Make sure to construct a similar header to what you currently have when you raise the height of the door opening. It would be helpful to see how your building foundation and floor are currently constructed before anyone can make an educated comment on what to do there, although pouring over a deteriorated slab is seldom a good idea.

http://www.garagejournal.com/forum/attachment.php?attachmentid=166226&d=1328030626 That is exactly what I was talking about when raising the ceiling...as for the floor a local concrete guy/friend said they have done a handfull of pours like this and have had good results. The option of raising the garage and tearing out the old slab and pouring a new one is not possible because of where it sits...to close to property line...wont issue a permit for that type of repair....So I can either cut the whole center section out and leave about a two foot perimeter of the floor around the two sides and back which wouldnt be bad because that space will be occupied by work benches and toolboxs etc. or pour over existing...six inches thick with fiber and wire. Garage is rarely used for car storage other than the occasional snow storm. I do use it to repair or maintane cars or trucks but its mostly just a workshop for motorcycles and other stuff. The local concrete guy said its moved as much as its gonna move and it would be fine....Just looking for a second, third , fourth opinion from others who may have done it not just think its a bad idea and have never tried it....I know its like polishing a turd,but its my turd and Im gonna make it shine