Chaps,
I have permission to extend out house, one aspect of which is building on top of the existing garage to put another bedroom/shower room.
The garage is single skin so will need a second inner lining wall. Now, subject to a couple of test digs to ensure existing footings are ok, can I
then build the second inner lining wall straight onto garage floor or should I remove this down to footings, build on that then backfill garage floor
to new wall.
Hope this clear
Cheers very much
ATB
Simon
Best to ask your building inspector. Almost certainly they'll want the wall rebuilding with cavity ties etc.
It would also depend on the construction of the original wall too.
It's got to bond with the footings which may not be wide enough and the new wall should be insulated and bonded to the old.
In reality it is easier, quicker and in the long run cheaper to knock the old wall down and start again.
Building regs on this must be followed
can't you build the second skin on the outside? save you losing garage space.
wouldn't think you will be able to build of the garage floor. it will possibly only be 4" of concrete on top of a bit of hardcore.
its a few years since i've had anything to do with this sort of work but last time i did something similar building control made us dig down to
the bottom of the original footings and pour more concrete to create new footings for the extra wall
I've done this before.
You have no way of verifying the suitability of the garage floor for carrying the additional load, short of cutting through it, but that'
doesn't confirm what steel if any is in there.
The one we did, we had to cut a channel out of the floor, dig down to foundation level, tie new foundations to the existing and then build off that.
You have to dig down to the bottom of your footings to make sure that you have the right depth and width of the footings to be able to take the safety
of your new building above. See a builder who will tell you what depth and width you will need to be certain that it passes building regs.
Once that you are positive that your footings is correct you can start building, don't forget the cavity, and as you are building up you will
need to put ties in to strengthen both skins.
This is the hard way. The easy way will be to knock down and start all over and be right from the word go.
One thing I advise is to keep in with all building regs and the planning department.
quote:
Originally posted by silverback
You have to dig down to the bottom of your footings to make sure that you have the right depth and width of the footings to be able to take the safety of your new building above. See a builder who will tell you what depth and width you will need to be certain that it passes building regs.
Once that you are positive that your footings is correct you can start building, don't forget the cavity, and as you are building up you will need to put ties in to strengthen both skins.
This is the hard way. The easy way will be to knock down and start all over and be right from the word go.
One thing I advise is to keep in with all building regs and the planning department.
quote:
Originally posted by zilspeed
quote:
Originally posted by silverback
You have to dig down to the bottom of your footings to make sure that you have the right depth and width of the footings to be able to take the safety of your new building above. See a builder who will tell you what depth and width you will need to be certain that it passes building regs.
Once that you are positive that your footings is correct you can start building, don't forget the cavity, and as you are building up you will need to put ties in to strengthen both skins.
This is the hard way. The easy way will be to knock down and start all over and be right from the word go.
One thing I advise is to keep in with all building regs and the planning department.
One bit I disagree with here.
A builder knows how to build stuff, not how to design stuff.
An engineer is required for the design.
Granted there are a great many that would get it right, but you're asking him to do a job that he's not qualified to do.
You need an engineer, that way you're buying liability insurance.
I don't think there's actually any need to apologise, so please don't.
P.S. Welcome to the forum.
quote:
Originally posted by zilspeed
I don't think there's actually any need to apologise, so please don't.
P.S. Welcome to the forum.
Firstly, it is not acceptable to build off the existing floor slab in most instances, I'd suggest that you should investigate the existing
foundation, it will probably be of insufficent width to accomodate the additional leaf of masonry.
It has already been said about builidng your new leaf of masonry on the outside of the garage and this is the way I would normally recommend. It will
result in the garage not being reduced in size and the new room above will be in the order of 300mm bigger in each dimension.
Should the foundation be of insufficent width it is very simple tp overcast the scarcement and dowl into the existing to provide a suitable
foundation. Additionally you will not need to break out the garage floor and a dig to the outside of the garage is likely to be easier too.
We need to see some drawings/photos to properly help you explore your options.
Cheers R
Ours is on the left, neighbour on right did what we are planning to do - except our garage will be extended roadward by 10 feet and the porch by 5
feet
Neighbour has converted garage to study, we won't be.
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house
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Appreciate about tieing walls and insulation etc.
Prob best to place new wall on footings rather than onto floor or garage. Next door built new wall outside existing.
Will be doing building regs drawings soon so will mentioned to regs officer.
Cheers chaps
ATB
Simon
[Edited on 18/1/12 by Simon]
Copying what the neighbours did will certainly be looked upon kindly by the local authority. When you say "permission" did you mean planning
permission or other half's permission? 
You've done well if you got planning permission to extend the garage forward, that's not generally allowed. I suppose you don't have
enough space to widen the garage, developers always make their garages too bloody narrow to be useful 
Planning permission granted
Ours and the neighbour being in the round bit of the close are set back from the neighbours to the left of our house by
about 25', so we are behind any sightlines.
Means I'll have a nice size empty garage (gotta sell toy car to help pay for it) but plenty of room for the next project
ATB
Simon
quote:
Originally posted by Simon
Chaps,
I have permission to extend out house,
Simon
The people I sent the plans and my money to - Tunbridge Wells Borough Council
No "out house", that was a typo that should read "our house"
ATB
Simon