We're having a largish shed built at our golf club to store our golf buggies (3 of them). The base is concrete, 8.6m x 2.0m.

Unfortunately the concrete base is not level (I won't bore you with the reasons why!)One corner is approx 50mm lower than the others which is preventing us from erecting the shed itself and getting it square. I'm thinking of laying a further layer of concrete on top of the existing concrete, say about 25mm thick, which would taper to 75mm thick in the low corner IYSWIM. Is this feasible? Does it need any bonding between the existing surface and the new concrete?

TIA
Pete

On 12/06/15 11:56, petek wrote:
We're having a largish shed built at our golf club to store our golf
buggies (3 of them). The base is concrete, 8.6m x 2.0m.

Unfortunately the concrete base is not level (I won't bore you with
the reasons why!)One corner is approx 50mm lower than the others
which is preventing us from erecting the shed itself and getting it
square. I'm thinking of laying a further layer of concrete on top of
the existing concrete, say about 25mm thick, which would taper to
75mm thick in the low corner IYSWIM. Is this feasible? Does it need
any bonding between the existing surface and the new concrete?

TIA Pete


Yes and you will need SBR for this (because you are going thin at one end):

http://www.bostik.co.uk/diy/product/.../technicalData

The PDF there has everything you need.



Another question: Do you need the floor level or just the shed frame? If
so can you

a) Stand the frame on Wallbarn adjustable stands

b) As the screed, but just run a wall of it around teh edge to mount the
frame on.

On Friday, June 12, 2015 at 12:22:00 PM UTC+1, Tim Watts wrote:
On 12/06/15 11:56, petek wrote:
We're having a largish shed built at our golf club to store our golf
buggies (3 of them). The base is concrete, 8.6m x 2.0m.

Unfortunately the concrete base is not level (I won't bore you with
the reasons why!)One corner is approx 50mm lower than the others
which is preventing us from erecting the shed itself and getting it
square. I'm thinking of laying a further layer of concrete on top of
the existing concrete, say about 25mm thick, which would taper to
75mm thick in the low corner IYSWIM. Is this feasible? Does it need
any bonding between the existing surface and the new concrete?

TIA Pete


Yes and you will need SBR for this (because you are going thin at one end):

http://www.bostik.co.uk/diy/product/.../technicalData

The PDF there has everything you need.



Another question: Do you need the floor level or just the shed frame? If
so can you

a) Stand the frame on Wallbarn adjustable stands

b) As the screed, but just run a wall of it around teh edge to mount the
frame on.

If the shed can be a little taller, lay a very low dwarf wall round the edge to support the frame ? Might also help to protect the frame if it is timber.

Simon.

Doing the latter for a greenhouse has resulted in a lot of break up of the
smallish pile of concrete over time, presumably from water and frost and the
puddling effect due to the slope of the original concrete it was built on,
so I'd have reservations about how long it might last.
My feeling might be to build it on something substantial like some wooden
beams with them levelled by using some wood cutting, and use a floor
inside the shed made of wood.
Of course one needsto retreat the wood where its been cut.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Tim Watts" wrote in message
...
On 12/06/15 11:56, petek wrote:
We're having a largish shed built at our golf club to store our golf
buggies (3 of them). The base is concrete, 8.6m x 2.0m.

Unfortunately the concrete base is not level (I won't bore you with
the reasons why!)One corner is approx 50mm lower than the others
which is preventing us from erecting the shed itself and getting it
square. I'm thinking of laying a further layer of concrete on top of
the existing concrete, say about 25mm thick, which would taper to
75mm thick in the low corner IYSWIM. Is this feasible? Does it need
any bonding between the existing surface and the new concrete?

TIA Pete


Yes and you will need SBR for this (because you are going thin at one
end):

http://www.bostik.co.uk/diy/product/.../technicalData

The PDF there has everything you need.



Another question: Do you need the floor level or just the shed frame? If
so can you

a) Stand the frame on Wallbarn adjustable stands

b) As the screed, but just run a wall of it around teh edge to mount the
frame on.

On Fri, 12 Jun 2015 03:56:39 -0700, petek wrote:

We're having a largish shed built at our golf club to store our golf
buggies (3 of them). The base is concrete, 8.6m x 2.0m.

Unfortunately the concrete base is not level (I won't bore you with the
reasons why!)One corner is approx 50mm lower than the others which is
preventing us from erecting the shed itself and getting it square. I'm
thinking of laying a further layer of concrete on top of the existing
concrete, say about 25mm thick, which would taper to 75mm thick in the
low corner IYSWIM. Is this feasible? Does it need any bonding between
the existing surface and the new concrete?

We've just had exactly this with an outbuilding floor. Unfortunately for
us, ours needed to go up ~75mm at one corner - but 0mm at the diagonal
opposite.

If it was all at least 20mm+, it'd be an easy screed, I was assured.
Thinner than that, there's a risk of it breaking up.

Prep was apparently no more than a bloody good clean up, then PVA and
sand to give a key. Can't hurt to go over the surface with something like
a grinder to score for a key, though.

On Fri, 12 Jun 2015 16:28:30 +0000, Adrian wrote:

We've just had exactly this with an outbuilding floor. Unfortunately for
us, ours needed to go up ~75mm at one corner - but 0mm at the diagonal
opposite.

Should add that we went for the nuclear option. Break it all up, get it
all out (two guys, 1.5 days (but could easily have been one), stihl saw
and road-breaker drill), new plastic, and re-lay. It looks lovely now,
but... wince

"petek" wrote in message
...
We're having a largish shed built at our golf club to store our golf buggies
(3 of them). The base is concrete, 8.6m x 2.0m.

Unfortunately the concrete base is not level (I won't bore you with the
reasons why!)One corner is approx 50mm lower than the others which is
preventing us from erecting the shed itself and getting it square. I'm
thinking of laying a further layer of concrete on top of the existing
concrete, say about 25mm thick, which would taper to 75mm thick in the low
corner IYSWIM. Is this feasible? Does it need any bonding between the
existing surface and the new concrete?
---------------------------------
---------------------------------

You can lay the concrete at 50mm but not at 25mm as the stones tend to ride
over the top of each other at such small depth, meaning you can't get a
decent finish and also, it doesn't achive full strength and will break up.

Better to use a sand/cement screed, you can get these ready mixed and
delivered or order the raw materials and mix it yourself, 4 grit sand to 1
cement, don't mix it too wet, and the existing floor will need a good
soaking in this weather, followed by a coat or two of PVA or SBR prior to
laying