Silver maple - Ask Extension
Hi,
I have 3 mature silver maples in my backyard, and I am curious as to how their root system may affect the integrity of a foundation. Specifically...
Knowledgebase
Silver maple #771033
Asked September 07, 2021, 11:40 AM EDT
Hi,
I have 3 mature silver maples in my backyard, and I am curious as to how their root system may affect the integrity of a foundation. Specifically, I am considering installing an inground pool near the edge of the canopy of a silver maple, and my landscaper stated concern that the root system would be drawn to the underground condensation surrounding the pool, and possibly damage the liner. Is this a reasonable concern? Is there a minimum safe distance the pool should be located from a silver maple?
I would like to keep the maples, as they provide good shade for the rest of our yard, but I also don't want to worry about damage to either a pool or house foundation.
If we needed to replace the silver maples, is there an alternative, shade providing tree that has a root system that is safer around these other structures?
Thank you very much
Hennepin County Minnesota
Expert Response
Hello Mark, happy to help.
Tree roots actually grow well beyond their drip line as shown in the attached diagram of a tree above and below the soil level. The closer you get to the tree trunk, the thicker the root. Maples are notorious for their thick roots that can push up sidewalks and streets. Since most tree roots are in a relatively shallow pan and house foundations are usually much deeper than a sidewalk, tree roots don't usually endanger foundation walls because they don't find any water there. They simply turn sideways and probably run alongside the house. Clearly, if the trunk is very close to the house the thickening root can push against the foundation and crack it. This is why we don't recommend planting a tree close to a house among many other reasons. I think the same goes for pool foundations.
I haven't found any research on which tree roots are less of a problem for foundations than others. I would guess building a pool within the drip line of your trees may be asking for an issue later if not during construction. There's lots of good information about protecting trees during construction because cutting their roots introduces stress for the tree which can have consequences down the line. Here is some information to consider about protecting your trees during construction even if you site the pool well away from the trees, construction traffic can also have a detrimental effect on the trees.
Good-luck!
Tree roots actually grow well beyond their drip line as shown in the attached diagram of a tree above and below the soil level. The closer you get to the tree trunk, the thicker the root. Maples are notorious for their thick roots that can push up sidewalks and streets. Since most tree roots are in a relatively shallow pan and house foundations are usually much deeper than a sidewalk, tree roots don't usually endanger foundation walls because they don't find any water there. They simply turn sideways and probably run alongside the house. Clearly, if the trunk is very close to the house the thickening root can push against the foundation and crack it. This is why we don't recommend planting a tree close to a house among many other reasons. I think the same goes for pool foundations.
I haven't found any research on which tree roots are less of a problem for foundations than others. I would guess building a pool within the drip line of your trees may be asking for an issue later if not during construction. There's lots of good information about protecting trees during construction because cutting their roots introduces stress for the tree which can have consequences down the line. Here is some information to consider about protecting your trees during construction even if you site the pool well away from the trees, construction traffic can also have a detrimental effect on the trees.
Good-luck!
Hi,
Thank you very much for your help! To followup- it is reassuring to hear what you said about a house foundation being buried deep enough, and lacking water, such that root damage is less of a concern here. Would I be able to carry that assumption over to a buried, inground pool? I’m not sure if there would be concerns about condensation drawing roots to this area, unlike a home foundation, or not. I have heard of roots attacking a water pipe, but I’m not sure if a pool liner acts in the same way, or if it is more insulated.
The tree trunk of the maple wouldn’t be particularly close to the edge of the pool, but the edge of the pool liner would probably be buried close to the edge of the drip line.
Thank you again,
Mark
On Sep 10, 2021, at 7:11 PM, Ask Extension <<personal data hidden>> wrote:
Frankly, we're not pool experts nor am I familiar with anything about underground condensation. It remains to be a judgement call when it comes to how far away the trees are from the edge of the proposed pool and how thick the roots would be once they need to turn aside at the pool's edge. I recommend consulting a certified arborist to be sure. Here is a link to information about how to find and hire a professional.
Good-luck
Good-luck
