0

I have been concerned on cracks in my concrete basement floor. Home is 15 years old and always had one crack in the floor leading from the walkout basement door to about the center of the basement. This crack has never moved or got wider in any way. And it was always so dry in there i never needed a dehumidifier.

It was always very dry and warm down there. This winter it got wider and noticeable cracks moving through the whole basement.

I recently got a new metal roof in the spring of the year. It was strapped with wood and then metal on top. Right away water was going over the eaves troughs and corners of eaves are leaking.

I'm in the process of getting eavestroughs replaced with bigger eaves. Although there has been a far bit of water staying close to the foundation. Current drainage is downspouts going into a tile and then drains down to a bigger main tile. This appears to be clearing.

Could this excess water be the problem for the cracks is the floor? There is no sign of water in my basement. Just some moisture that was never there before. A bit of moisture on window frames.

Could the metal roof not be ventilating the house the same as it was, causing poor ventilation in the basement? The roof is now being ventilated through the peak.

I have an air exchanger which I don't run much during winter. So could that be the culprit of this extra moisture?

Grading around the foundation has settled. I'm assuming from the water flowing over eaves.

I'm very concerned on what are my next steps. To fix these sudden changes. In my mind it all stems from the new roof. Eavestrough overflow and I still feel the whole ventilation system changed through the installation of this very high cost roof?

I'm looking for recommendations. Answers. And a professional to assess the home. ASAP.

Your thoughts would be so helpful for thus stressful time.

Time is critical.

It's a 2000 sq ft one level home with a unfinished walkout basement.

1

2 Answers 2

2

All basement slabs crack. It's just a matter of where and whether adequate control joints were installed to prevent random cracking. You shouldn't really see seasonal movement, though. Yes, additional moisture around and under the foundation and slab could cause movement.

A change in roof type shouldn't change how water is handled around your home. Temporarily removed gutters could allow additional moisture to percolate into the soil near the foundation, and changes to grade or landscaping could also have an effect.

No, a metal roof shouldn't affect indoor humidity unless your attic ventilation is woefully lacking. Even then it wouldn't change much because not much moisture can migrate through a roof of any type.

1

A metal roof shedding snow unlike an alternative roof type could cascade into slab cracking in a basement. Poorly installed gutters is also plausible. Any water source.

Expansive soil grows when it gets wet and shrinks as it dries out. That is the likely cause of your slab cracking. As an alternative to roof runoff (a likely culprit given how the roof's state has been recently disrupted), a leaking pipe (presumably below the slab) or an unusually high water table could also supply the water for an expansive soil's swelling. An unusually low water table can also cause settling after years of stability, followed by cracking, but you've noticed unusually high humidity and water all over the place outside, so that seems unlikely.

There's a subset of clay soils that are expansive, and soil with organics is expansive. Unless your house is built over an old swamp or something, my best guess is that you got unlucky with an expansive clay soil. If you mitigate the water source that has caused the expansion, then the soil settles again over time and some cracks may close back to near their previous state. Unfortunately, sufficiently large steel reinforcement that is now bent could prevent the cracks from closing, where the steel wasn't strong enough to fight the expansive soil, but now the bent steel is strong enough to prevent the concrete from settling with the soil.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.