Hi all. Hope you guys can help me as previously.

Having just built a garage (concrete block construction). I am
about to cast a concrete floor.

However, as the floor is to be poured inside the walls, I am
wondering if I need to buid in some allowance for expansion. If
so, will it be sufficient to use wooden planking as formwork, but
just leave them in place. (Say, 2 feet from the walls all
around)? I am assuming that the wood will compress instead of the
floor pushing outwards.

Or.. is there a better system?

Thanks in advance.

Howard.


--
Howard Coakley
e-mail... howarddot}coakleyatcoakleydot].codotuk
Skype ID: howie10 (get skype from www.skype.com)

Howie wrote:
Hi all. Hope you guys can help me as previously.

Having just built a garage (concrete block construction). I am
about to cast a concrete floor.

However, as the floor is to be poured inside the walls, I am
wondering if I need to buid in some allowance for expansion. If
so, will it be sufficient to use wooden planking as formwork, but
just leave them in place. (Say, 2 feet from the walls all
around)? I am assuming that the wood will compress instead of the
floor pushing outwards.

Or.. is there a better system?

Thanks in advance.

Howard.

I've helped out on the construction of two (concrete block construction),
type garages and the Concrete base laid first and the concrete panels built
on the foundation.


--
Sir Benjamin Middlethwaite

I have done the same and got two different opinions - one from an
engineer and the other from a builder.

The builder was worried about expansion and recommended 10mm
polystyrene around the edge of the floor (i.e. between the walls on
the floor). The engineer (a friend whose views I would trust) was
worried about contraction. His view was that when concrete cures it
contracts. If it was in contact with the outside walls it could put
stress on the walls. He recommended bringing the DPC up the wall so
that the concrete floor was floating - i.e. did not bind with the
outside walls. Because it was a double garage we put an expansion
joint in the middle using 10mm polystyrene.

In the end I took the engineers advice. The garage has been standing
for about 7 years with no problems with the floor.


Hope this helps


Howie wrote:
Hi all. Hope you guys can help me as previously.

Having just built a garage (concrete block construction). I am
about to cast a concrete floor.

However, as the floor is to be poured inside the walls, I am
wondering if I need to buid in some allowance for expansion. If
so, will it be sufficient to use wooden planking as formwork, but
just leave them in place. (Say, 2 feet from the walls all
around)? I am assuming that the wood will compress instead of the
floor pushing outwards.

Or.. is there a better system?

Thanks in advance.

Howard.


--
Howard Coakley
e-mail... howarddot}coakleyatcoakleydot].codotuk
Skype ID: howie10 (get skype from www.skype.com)

Howie wrote:
as the floor is to be poured inside the walls, I am
wondering if I need to buid in some allowance for expansion.

What are the dimensions?

On Thu, 06 Oct 2005 11:14:55 +0100, Chris Bacon
wrote:

|Howie wrote:
| as the floor is to be poured inside the walls, I am
| wondering if I need to buid in some allowance for expansion.
|
|What are the dimensions?

Ahh yes, that might help! (Sorry).

Approx 4m W x 5m L.

On Thu, 06 Oct 2005 09:07:47 GMT, "The3rd Earl Of Derby"
wrote:

snip

|I've helped out on the construction of two (concrete block construction),
|type garages and the Concrete base laid first and the concrete panels built
|on the foundation.

Hmmm. Bit late for that though, isn't it? ;-)

Any ideas on floor expansion?

On 6 Oct 2005 02:28:07 -0700, "Frank"
wrote:

|I have done the same and got two different opinions - one from an
|engineer and the other from a builder.
|
|The builder was worried about expansion and recommended 10mm
|polystyrene around the edge of the floor (i.e. between the walls on
|the floor).

Right. This was the sort of thing I was thinking about. I suppose
it doesn't really matter if I have the gap slightly further away
from the walls? (It would suit the way I am pouring it much
better if I can).

|The engineer (a friend whose views I would trust) was
|worried about contraction. His view was that when concrete cures it
|contracts. If it was in contact with the outside walls it could put
|stress on the walls. He recommended bringing the DPC up the wall so
|that the concrete floor was floating - i.e. did not bind with the
|outside walls.

Fair enough. This will be OK anyway as I intend to put a membrane
down first and bring it up the walls to stop damp penetration
from beneath. I also plan to use a steel reinforcement grid as
there may be some heavy traffic in the future.

| Because it was a double garage we put an expansion
|joint in the middle using 10mm polystyrene.

Can't remember where you got it from, can you?
|
|In the end I took the engineers advice. The garage has been standing
|for about 7 years with no problems with the floor.
|
|
|Hope this helps
|
|
|Howie wrote:
| Hi all. Hope you guys can help me as previously.
|
| Having just built a garage (concrete block construction). I am
| about to cast a concrete floor.
|
| However, as the floor is to be poured inside the walls, I am
| wondering if I need to buid in some allowance for expansion. If
| so, will it be sufficient to use wooden planking as formwork, but
| just leave them in place. (Say, 2 feet from the walls all
| around)? I am assuming that the wood will compress instead of the
| floor pushing outwards.
|
| Or.. is there a better system?
|
| Thanks in advance.
|
| Howard.
|
|
| --
| Howard Coakley
| e-mail... howarddot}coakleyatcoakleydot].codotuk
| Skype ID: howie10 (get skype from www.skype.com)

I just cut long strips from 10mm styrofoam insulation. I got it in a
BM. They did it in sheets approx 2'x4'.


Howie wrote:


Can't remember where you got it from, can you?
|
|In the end I took the engineers advice. The garage has been standing
|for about 7 years with no problems with the floor.
|
|
|Hope this helps
|

On Thu, 06 Oct 2005 09:57:11 +0100, Howie
wrote:

Hi all. Hope you guys can help me as previously.

Having just built a garage (concrete block construction). I am
about to cast a concrete floor.

However, as the floor is to be poured inside the walls, I am
wondering if I need to buid in some allowance for expansion. If
so, will it be sufficient to use wooden planking as formwork, but
just leave them in place. (Say, 2 feet from the walls all
around)? I am assuming that the wood will compress instead of the
floor pushing outwards.

Or.. is there a better system?

Thanks in advance.

Howard.

I my house (block construction) , I put the DPM on the floor & up the
walls, then poured the concrete in. BCO has seen it, without
complaint.

Rick

OK. Thanks for all your help with this. I have sourced some
polystyrene expansion sheets and will go the route of one down
the middle, and all around the walls.