Blockwork as formwork

[pippo]

Hi

Is it ok to use 4" single leaf blockwork sitting on strip foundations as permanent shuttering for pouring a concrete base? Would it need any extra horizontal support other than the mortar holding it in place? The base is to be 6.2m x 3.2m and 6" deep.

Thanks

 

[noseall]

100mm dense conker blocks will deal with 150mm of concrete no problem.

Just make sure the masonry has had adequate curing time.

 

[Chukka63]

no mention of any hardcore/consolidating/wacking.as nose said,masonary needs to have several days curing this time of year to save risking it failing.

 

[jm2000]

i agree...7 days is what we usually ask people before the pour...less if its at dpm and cavity filled.

 

[pippo]

Chukka63: The strips are below GL so there will be 2 courses to take me 150 above GL. The sight is sloped and uneven so there will be varying depth compacted hardcore which will at all points be well over 4" as advised on this forum previously. The outside will be backfilled to GL.

I will be sure to leave it for at least 7 days before I do anything.

 

[Chukka63]

should be fine then.
the problems only come when the blockwork is quite high out the ground and lots of depth of hardcore is put in and then whacked and the walls can fail and bulge.dont forget youre suppose to whack every 150mm of hardcore.

 

[RedHerring]

Pippo, you didn't mention any piers. And you don't say how high you're going with the blockwork. I assume you'll be doing at least 2 meters high. I personally would have included piers in the corners and central piers in the long walls. These should have been allowed for in the strip foundations.
Perhaps the more experienced posters might give an opinion?

 

[pippo]

The blocks were done today. The guy done it on behalf of a concrete sectional garage company (no piers required) and he did them on edge so they are 9"thick and sized so that the 3" concrete sections sit right in the middle of them. They are now just above ground level.

I am having second thoughts on the concrete sectional garage now and fancy a insulated 2"x4" timber garage. The 9" blockwork wont be ideal for this as 5" of it will be exposed on the inside of the garage along with the dpm, I will probably start a new thread to discuss this.

Pippo

 

[Chukka63]

if youre getting timber,get a lugarde if you can afford it.

http://www.taylorsgardenbuildings.co.uk/store/customer/product.php?productid=20248

 

[JohnD]

one of my relations had a tractor shed rebuilt after an arsonist burned it down, and was surprised to find that rendered blockwork came out cheaper than timber frame and cladding.

IMO it is also a superior building to the old one.

 

[Deluks]

You can always stud out and insulate the inside of the concrete sectional jobbie.