Dodgy 100mm concrete blocks

fuchia

Hi All,

Inspite of the brutal weather we are near finishing the block work on our two story house. We went for 100mm cavity wall construction with 150mm cavity.

We are getting the blocks from a large national supplier.

All was going well untill the last load arrived. The blocklayer was on to me straight away. The blocks were warped up to 5mm and very brittle.

I called the block company rep and he came out and agreed to replace them. The next load is better but still not as good quality as the first blocks we got.

Is there any way to tell the quality of the blocks apart from getting them crushed?

Could I ask for test certs from the supplier?

The rep wants me to use the blocks and he will "do me a deal" on them but I am not keen on using what I think is substandard materials.

Any advice would be appreciated.

Regards,

Fuchia

Joey the lips

If he does you a deal there is something wrong. I would not trust them. In fact as its the second load. I would go to another supplier.

10-10-20

The engineering department in any university would be only too happy to assist you in determining whether these blocks are within spec or not.
We've used them for electrical devices in the past.

Penn

Joey the lips wrote: »

If he does you a deal there is something wrong. I would not trust them. In fact as its the second load. I would go to another supplier.

I agree. Him saying that he'll do you a deal just doesn't sit right, particularly if they don't seem to be up to standard. I would have expected good blocks on the second load, seeing as how they gave you bad ones the first time. I'd be tempted to tell them he can do you a deal but on a new load that have to be of good quality. Otherwise you'll go elsewhere.

Then again, as Joey The Lips said, you're probably just better off going to another supplier anyway

mickdw

Dont use them blocks. If they are under strength, the build could become a disaster zone with everyone washing their hands of it leaving you, the block company & your solicitors to sort out the structural failures.
Im not a legal person but accepting a known defective product for a reduced cost might not help if problems did arise.
And yes as was said above, get Department of Engineering at a college to test block. I know IT Sligo do/did this as a commercial enterprise while giving us plenty of material for messing with when in college

cork1

just out of curiosity are they a limestone block or a sandstone block. we tend to stay away from sandstone block thess days notice alot more cracking witht them

fuchia

Thanks for all the replys.

I dont know what the blocks are made from.

I have contacted a company in Limerick that will test the blocks for me.

Will have the results in a couple of days.

Fuchia

fuchia

Hi All,

I just wanted to let ye know how I got on.

The company in Limerick crushed ten blocks.

The results were between 5.2N and 8.3N

The guy that tested them said that while all the blocks passed the test the variation in the results was too wide. This was due to aggregate segregation which makes the blocks brittle.

The aggregate segregation was most lightly due to a problem with vibrating plant used in the manafacture of the blocks.

After much hassle the block supplier agreed to take the blocks back and I am now using a different supplier.

I have recently heard of other building sites in the area that have had the same problem.

I am so glad I stuck to my guns and did not use those blocks.

Fuchia

AckwelFoley

i in my time have done blocks on my own house and a few others, so in my time ive laid about 30,000 of them.. (which is not a huge amount)

"Warped" blocks ive never come across, however its perfectly normal for blocks that come straight from the supplier that made them to be "brittle" Infact, laying a fresh load of blocks is easier beacuse cutting them is less work than when they get harder.

Concrete take years to reach full strength, but it generally is considered to reach half strength by 28 days