Excavating Next to Trees 6

[cieg22]

Hello. I'm accustomed to heavy-handed commercial projects, and I'm trying to adapt to residential. I'm working on a proposed house on a lot with mature trees that include a 40" American Elm, 12"-16" White Pines, a 20" Ash and a 24" Silver Maple. The house will include a basement.

I'm trying to keep as many trees as possible. Our excavation will affect the roots(I've read that these species have shallow, wide root systems that can spread beyond the canopies).

Are there any guidelines about how much of a root system can be taken away without compromising trees? I've read that new trees should be planted at least 10' from buildings, but I assume this is a different situation.

Thanks in advance for your help.

 

[hokie66]

The pines should be no problem, as they have a tap root extending straight down. The others will likely be problems. The same rules should apply to old trees as to new. Not too sure about the elm and ash, but silver maples are notorious for getting into pipes and heaving footings.

I would ask an arborist or gardener for advice. Your state forestry department would be another source.

 

[msquared48]

The maple sounds like a lot of good firewood to me. I agree with Hokie. I am going to have to repair a part of my driveway due to one 10 feet away. Not enough distance there... maybe 50 feet.

Mike McCann
MMC Engineering

 

[soiledup]

Whats teh soil? Best check the swelling potential before sticking foundations too close.

 

[bridgebuster]

Your best bet is to call an arborist. IN NY city, we deal with this quite often on street projects. We always need an arborist to decide how much of the roots can be cut; there's no one rule for all trees.

 

[bridgebuster]

One other point - sometimes when you trim the roots you also need to prune some branches.

 

[dicksewerrat]

Th silver maple is not really a good hardwood tree. they break fairly easily in high winds. I would try to save the ash and elm. But don't build close enough for branches overhang the building. Pines could be lost and then replant.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[bimr]

Try these links:

http://www.extension.umn.edu/distribution/housingandclothing/DK6135.html

http://mdc.mo.gov/conmag/1998/05/30.htm

 

[dik]

I often consider the 'drip' line. This is the outward extremety of the branches.

Dik

 

[lovethecold]

Whats teh soil? Best check the swelling potential before sticking foundations too close.

As soiledup says, be cognizant of the type of soil at the site. If it is a highly expansive fat clay that has been dried out due to the trees, the soil will likely regain some moisture content after the removal of some of the trees. This would require an overdig. Otherwise the soil will swell causing unwanted heaving and cracking of the home. We see this fairly often in heavily wooded areas next to rivers and streams, usually after the fact.

 

[ptmoss]

I do a lot of residential work and I agree that a call to an arborist is the best way to go. I've found state forestry people and other groups tied to universities that offer "free" services to be a bunch of weinies that won't give targeted advice if there's the slightest liability involved, and that's if they'll even come out and look.

Also, with the pines, realize that they sometimes rely pretty heavily on the trees around them for support from wind and when you remove some it leaves the others very susceptible to falling. I see this a lot.

 

[cvg]

many trees roots extend well beyond the drip line. Depends on how they are watered. If there is a lawn sprinkler system, roots tend to be more shallow. If no sprinklers, than roots are generally deeper. Best to consult an arborist

 

[cieg22]

You guys are the best!
A similar issue just popped up on another project. We need to run a sanitary sewer parallel to a line of mature spruce trees (16" to 24", with 12'canopy radius). I'm definitely going to put your advice to good use on this one. (Including recommending that we consult an arborist.) If anyone has further comments about this, please let me know.

Thanks again, everyone.