New House. Old Roots.

[Jim Katen]

Brand new house. Just passed its final inspection two days ago.

In the crawlspace, I found several roots poking up out of the ground. Some are as big around as my finger. Some as big as my wrist. There are not trees anywhere near the building site.

Clearly, the builder failed to "remove all vegetation and organic material" from the foundation zone. The question is, what bad thing will happen as a result.

When I emerged from the crawlspace, I was pretty gloomy on that front. I told the buyer that the roots would rot, attract wood-destroying insects, and create voids in the soil that might - maybe - cause the interior round footing pads to move.

Now I'm thinking that I was too harsh. Even if the small roots that I can see connect to larger ones, say 6" diameter ones, the likelyhood of them causing any significant settling seems like it would be close to zero.

I'm trying to formulate my report, but I find that I'm hobbled by a lack of experience with this condition. Has anyone had bad experiences with old dead roots causing damage to a house?

[John Kogel]

I had one footing holding a post under a beam that settled about an inch. Dirt crawlspace. No other footings moved so I surmised that a rotten root collapsed under there. This was a cottage in the bush, poorly prepped site to say the least. Nothing bad happened, I pounded in a shim and gave it my blessing.

There were dampwood termites under there. I found a small stump that had been completely hollowed out like a thin bowl. They never attacked the structure, just the half-buried roots and stumps. But that is one concern with finding roots under the house.

[Jim Katen]

I had one footing holding a post under a beam that settled about an inch. Dirt crawlspace. No other footings moved so I surmised that a rotten root collapsed under there. This was a cottage in the bush, poorly prepped site to say the least. Nothing bad happened, I pounded in a shim and gave it my blessing.

There were dampwood termites under there. I found a small stump that had been completely hollowed out like a thin bowl. They never attacked the structure, just the half-buried roots and stumps. But that is one concern with finding roots under the house.

Yeah, the bug issue is easy to deal with. I'm just wondering about the likelihood of undermining.

[Dale McNutt]

After building many homes in the Sierra Nevada foothills, (all with crawlspaces) some 25-odd years ago, I would simply offer up, "don't sweat it". We encountered numerous pine and oak roots. The concern was never raised by anyone.

[Chad Fabry]

When I first moved into my current home, I removed a huge dead poplar tree. I dug the stump out; a two day assault with a backhoe. the stump was so big that I had a hole that was big enough to drive into and out of. Anyway, fast forward a year and you'd find me placing an exposed aggregate slab near, but not on the excavation zone.

Now, 15 years later, that exposed aggregate patio is broken. The roots rotted below one end and a huge triangular chunk is tipped into the void left by their inconsiderate decomposition.

[Marc]

My father removed a row of perhaps 15, 20 large mature pine trees on his property in the early 80's while I was away at college. In the mid 90's, it took halfway a wheelbarrow of dirt at each site to fill the cavities left by the rotted stumps. None were deeper than about 18".

Marc

[ghentjr]

Clearly, the builder failed to "remove all vegetation and organic material" from the foundation zone. The question is, what bad thing will happen as a result.

The stump in the picture was buried since 1967 when my house was built. It was excavated two months ago. I may depend on soil and moisture as to whether the stuff you saw will cause harm.

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[Nolan Kienitz]

Down here in the land of Post-Tension Slabs decaying tree roots can be a pox on the foundation's "well-health".

Couple the rotted root voids that are created along with the clay soils that constantly expand/contract and there is a recipe for moving/failing slabs and the need for after-market piers.

On the other hand your soil conditions are different and it is a pier & beam.

I've been under many pier & beam homes (circa 1925 to 1935) in the Dallas historic district with bois d'arc tree trunks as piers and also see many tree roots that have not appeared to cause any problems.

[Phillip]

In some of the older homes I have done where you could tell that there had been roods there because of the voids in the dirt most of them did not have any damage from the rotten roots. A few had some damage.

I guess it would depend on where the roots are and how large are the one you cannot see.

I would go with what you told them to start with.

[Brandon Whitmore]

I inspected a 30-40 year old home a while back that had significant settlement of pier pads in areas (post/ beam). Based on memory, some of those pads had dropped 6-8" over that time. As is typically the case, the beams had not settled, at least not much; the posts were just free hanging.