Uneven and bulging concrete floor. Sulphate attack? (with pictures)

[stuart45]

The 2 terms I've always used are Tarmac(hope I don't get sued ) or Asphalt. I was going to Tarmac the lounge but the wife wouldn't let me bring the roller down the hall.

 

[ajstoneservices]

And waiting at the temporary lights is a 8itch too.

 

[bigdrew]

So I think I'm digging the floor up! I've broken open one of the cracks at the edge of the room and there doesn't appear to be much under. I made a small hand size hole and could get most of my arm under. There are a few damp bricks wedged in but nothing in the way of compacted hard core. This could be as I've only looked at the edge - but it doesn't paint a good picture!


So far I've checked both walls are on separate foundations. I know where the gas runs (Plus its off) All electricity is off. I'm not sure where the water runs - is where any way for me to find out. Looking at the stop cock outside and where it comes into the house I've got a rough idea but not too sure. Anything else I should look into? Probably a prime underfloor heating time!

Woody (Or anyone else in the know) you have recommended that I go to the bottom of the foundations. In other threads you have suggested leaving the current in fill down compacting it and put a new slab on top ensuring that there is a good membrane separating them. https://www.gov.uk/government/uploa...le/429208/sulphate_damage_research_report.pdf This .gov document recommends both methods. One is a fair bit more work than the other - How do I identify if it is necessary to remove all?

Thanks,

Andy.

 

[^woody^]

In other threads you have suggested leaving the current in fill down compacting it and put a new slab on top ensuring that there is a good membrane separating them

Did I? Was it situation specific? I don't remember

If the fill is left down, then there is a risk of further sulphate production and this moving sideways to the walls and foundations.

So if this is unlikely - such as the initial attack was brought on by an increase in ground water which has since been rectified, or the fill is low volume and low risk, then yes it can stay. It's all about assessing the cause and potential future risk.

BTW you should make a building regs application, and the new slab should be insulated to current standards. This will also help with any future sale as it will be a means of proving that the floor has been replaced - some lenders wont lend on properties in known areas unless the the floor has been replaced and certified.

 

[bigdrew]

//www.diynot.com/diy/threads/sulphate-attack-replace-with-concrete-or-suspended-timber.246433/

This was the thread I was referring to. I think I've miss interpreted! I'll dig the lot out! Not the sort of job I fancy doing twice..

I don't suppose you can recommend any labs I can send samples to directly? (Most of the companies advertise for core drilling and I am assuming they send the samples of to a separate labs anyway!?)
I know it won't matter once its replaced - but it would be nice to have a understanding of whats happened if it isn't going to cost too much

Thanks - I have be recommended a local private inspector.

 

[Nige F]

Nige F,

I'm still waiting for an answer?

Are you still waiting?