I've read about products that you can buy to put on the footer, before the basement wall is poured, that stop the "rising damp" - or wicking of water up from the footer into the basement wall. I've checked around here, and no one that I've talked to (a few concrete guys, a waterproofer, a residential architect) have ever heard of or seen this used in our area.

I have not purchased a any special product for this (like the membrane from Delta (?)). But I read on a GBA Q&A that someone recommended just painting Drylock onto the footer.

They started digging the basement today. All of the dirt that came out of that 7 foot deep hole was a lose loamy dirt - no rocks, no clay ... to my untrained eye. We are on the high area of the property. We'll have form-a-drain in the footers to a daylight drain. I'm wondering:

- Should I get the drylock to paint the footers?

- Do you think the concrete guy would have any reasonable objection or concern if I paint the footer? It won't be keyed but we'll have rebar from the footer up into the wall.

- How long after it sets up can do I wait to paint it. Generally they'll want to pour walls the next day - so this isn't a big window unless I delay the wall pour.

And just an off-side question for those in the concrete-know... We're having temps in the high 80's low 90's. Should I take efforts to keep the footer concrete damp after the pour (counter to the Drylock painting effort!).

- For example, I could use water from our rain barrel (only ~40g)
- or I could cover it with clear plastic sheeting (but I don't know if it will get TOO hot with the clean plastic and sun beating on it, and ruin the cure somehow.

All these nitty picky detail questions - I'm just full of 'em. I really appreciate the help from this group. Thanks!

We're having temps in the high 80's low 90's. Should I take efforts to keep the footer concrete damp after the pour (counter to the Drylock painting effort!).

Concrete will eventually cure harder if you keep it wet, but is the extra effort necessary? Your readi-mix company should prepare a mix suitable for the temperatures expected that will achieve the specified strength you need.

You could use the Drylock if it will give you peace of mind, but it sounds like your soil is porous and well-drained and you have good footing drains to boot. Unless rising damp is a known problem in your area, is it worth the time and expense?

Are you using a fly ash concrete mix?

Posted By ICFHybrid on 05 Jul 2011 11:28 PM

We're having temps in the high 80's low 90's. Should I take efforts to keep the footer concrete damp after the pour (counter to the Drylock painting effort!).

Concrete will eventually cure harder if you keep it wet, but is the extra effort necessary? Your readi-mix company should prepare a mix suitable for the temperatures expected that will achieve the specified strength you need.

You could use the Drylock if it will give you peace of mind, but it sounds like your soil is porous and well-drained and you have good footing drains to boot. Unless rising damp is a known problem in your area, is it worth the time and expense?

Are you using a fly ash concrete mix?

I would be agreeing with you, Concrete material surely is much harder and has got great strengths as well....

Posted By ICFHybrid on 05 Jul 2011 11:28 PM

We're having temps in the high 80's low 90's. Should I take efforts to keep the footer concrete damp after the pour (counter to the Drylock painting effort!).

Concrete will eventually cure harder if you keep it wet, but is the extra effort necessary? Your readi-mix company should prepare a mix suitable for the temperatures expected that will achieve the specified strength you need.

You could use the Drylock if it will give you peace of mind, but it sounds like your soil is porous and well-drained and you have good footing drains to boot. Unless rising damp is a known problem in your area, is it worth the time and expense?

Are you using a fly ash concrete mix?

I don't really want to spend the extra effort keeping it wet .... but if it needed to be done I would do it. It is only a one-time effort for a long term payoff - so for those things, I'm willing to put out quite the effort. But it sounds like the ready-mix plant compensates for the temps already, which makes sense. So, I'm off the hook.

It does seem as if the soil around here drains well, so if the "rising damp" thing is more for building in swamps ;-) I'm good with that - no drylock. Once again, it's just that I get one opportunity and the cost of the material and DIY effort is small compared to the entire project costs so I thought I would ask.

Not sure on the fly ash ... is there a reason you ask?

Thanks for your quick reply!

The least hassle way to keep exposed concrete moist (which is required to achieve the rated strength) is to spray it with curing agent. For rising damp, you could add something like "Hycrete".

Not sure on the fly ash ... is there a reason you ask?

Specifying a fly ash mix is not only "greener" from the standpoint of the energy required to make the materials, but it gives you a better concrete on both of the counts you are worried about - permeability and cure strength.

A capillary break between the footing and wall is cheap insurance, and would allow you to insulate the inteior of the foundation wall without needing to keep the vapor permeablity high. A second capillary break between the foundation and foundation sill is also still in order.

Just because the soil was dry when you dug out the footings is no guarantee that it's that way year-round, or will remain as-dry after you drain your roof adjacent to the foundation.

Posted By Dana1 on 06 Jul 2011 01:26 PM
A capillary break between the footing and wall is cheap insurance, and would allow you to insulate the inteior of the foundation wall without needing to keep the vapor permeablity high. A second capillary break between the foundation and foundation sill is also still in order.

Just because the soil was dry when you dug out the footings is no guarantee that it's that way year-round, or will remain as-dry after you drain your roof adjacent to the foundation.

Thanks a lot for sharing such detailed information....