Trees falling on homes?

[Grenfell]

Just a general question -

I often hear people worrying about large trees near their homes falling due to storms, high winds, etc.

How valid a worry is this?

In my neighbourhood, there are many large eastern white pines (70-100'). These trees have obviously been here quite a while (some over 100 years, I'd wager). Also many oaks (pin, red, bur) and mature red and sugar maples. They've withstood many storms and weather extremes over those years, I'd also wager.

So, assuming the tree in question is essentially healthy - good form, no trunk rot, etc. what is the actual danger of it being blown over?

I'm thinking it's minimal and people are playing to fears from 'old wives' tales' passed down through the years rather than actual fact. Several healthy specimens have recently been felled in my area and it saddens me as there doesn't appear to be a reason I consider valid. A rotted, decaying tree I could understand, but healthy ones?

Just curious...

 

[computeruser]

Having had trees fall on my home and in one instance make their way straight into the kitchen when I was a child, and having cut up trees that fell on other people's homes since then, I think that it is always a risk. How much of a risk will depend on the type of tree, physical condition of the tree (health, branching pattern, etc.), whether or not major roots have been severed/removed (as part of driveway/sidewalk installation, for example) and the combined presence of wind + heavy ice. The latter factor - ice + wind - is a frequent source of trouble around here (Great Lakes area) in the early spring when you get that last snowfall/ice storm of the season; multi-trunk trees or those with multiple leaders often split at a crotch, dropping half the tree and necessitating the removal of the remainder.

Would I categorically remove all big trees from around a house? No, not on a bet. But I would certainly make sure that my homeowner's insurance was current and adequate to promptly respond to tree-inflicted damage, should it occur.

 

[xtremetrees]

Yeah I ran across a bettle infested forest around the house last year. I told the home owner they were dead, she suggest trade a dirtbike for the tree just to down. I said sure. Well, they never called back. I went on a mission for the US Army, returned and saw their house. It was caved in from two dead pines. They had to forclose on the house I assume but certainly had to move it looked like the house had caught fire, the fallen dead pines took the powerline with it.

 

[Dadatwins]

Also consider a group of live trees offer support to each other, intertwined root systems, wind buffers ect. It has been my experience that a single stand alone tree will usually uproot more often than a tree that is in a cluster. Believe it or not uprooted trees that are located right next to house will usually cause less damage than one 50 ' away that builds up momentum on the way down. Sad thing is most folks cut down the ones closest to the house first for a false sense of security. Of course soil conditions, construction, root damage and overall health of the tree is always a factor in whether a tree will fall over. Dead trees are another story, they WILL fall over if left standing and should be removed ASAP especially if there is a possible target (house)
If you are concerned with your tree conditions contact a local arborist and have someone check them out. Good luck.

 

[Grenfell]

Thanks for the replies! I'm not concerned personally, it's more of a casual observation on my part that there seems to be a somewhat prevalent attitude of - "if the tree is big, it's going to come down!" I'm just wondering how much truth there actually is to it.

My neighbourhood was just an example since it is an older neighbourhood, nestled within our city's greenbelt, with plenty of large and mature trees.

 

[rebelman]

computer user mentioned multiple trunks splitting at the crotch. Way common.
I've found that many seemingly healthy trees will topple because they have no roots to speak of. Decades of root zone neglect or abuse is a huge problem. The tree looks fine, thick green carpet of bermuda grass, then bam you see what's been going on under there. Changing the culture concerning root zones is a challenge for Arborists as a group. Establishing ANSI standards for pruning was a major hurdle, now root zone issues must be addressed. Sound dramatic? It is.

 

[turnkey4099]

Thanks for the replies! I'm not concerned personally, it's more of a casual observation on my part that there seems to be a somewhat prevalent attitude of - "if the tree is big, it's going to come down!" I'm just wondering how much truth there actually is to it.

My neighbourhood was just an example since it is an older neighbourhood, nestled within our city's greenbelt, with plenty of large and mature trees.

It depends a lot on weather conditions in the area. An example is Spokane WA. Many, many mature Ponderosa pines and other trees in good health throughout the city. It is rare for a year to go by without at least one house catching a tree. We are subject to very high wind gusts. Also just watching the national news about storms, you see trees on houses all the time. No, it is not an assumption that a tree is going to come down because it is big. It is an assumption that big trees + big storms cause trees to come down leaving out the question of dying/diseased trees.

From casual observation, it is not steady, sustained winds that bring down healthy trees, but changeable, gusty blasts.

Harry K

 

[treeseer]

Great points by Dada. This from an article in TCI mag last Oct:

Arborists cannot remove all tree risk, unless we clear-cut the entire planet. Our job is to mitigate risk, by providing clearance for wires or roadways or cars, and maintaining health and stability. At times we must remove branches, or entire trees, but sometimes removing trees increases risk. When a client wants that big tree near the house cut down because they fear it, a few reminders are in order:

1. The worst-case scenario: Let’s assume that the tree uproots in a major storm, and falls toward the house. First of all, setting wind exposure and other factors aside, the tree is more likely to fail away from the house, because construction damage, restricted root area and soil compaction tend to limit anchorage toward the house. If we still assume that the tree may fail toward the house, the closer to the house it is, the less velocity it will have, and the less damage it will cause. That seventy-foot tall tree that’s fifty feet away will do more damage, so where does risk end? In the past, FEMA recommended removing every tree that was tall enough to hit the house, but few will go along with that
2. What about the “edge effect”? Just as removing a branch exposes other branches to increased stresses, the nearby trees will no longer have that big one near the house sharing the wind with them, and so they will be more vulnerable. They have developed enough girth to stand, but they are not used to standing on their own. It will take years for them to add enough trunk tissue to make them stable, and the perfect storm may arrive in the interim. So in some cases, mitigating the risk from that big tree by pruning and root invigoration may make the house safer than removing it entirely.

 

[Avery]

Treeseer,

You succinctly summed up some of what worries me, and what I didn't understand. I'm surrounded by huge pines and I assumed that the closest ones were the most dangerous.

Now I'm looking further afield at the ones that are the true menaces. Lucky for them --and unlucky for my home-- they're fairly unreachable. Like I said elsewhere in this forum, when it blows hard from the NW I pack up the fam and go on a day trip...

Avery

 

[treeseer]

If the wind blows at night, do you take the fam on a night trip? :jawdrop:

Keep the grove intact, and it will be more secure. I'm surrounded by pines, and stayed up to watch them dance in a 70 mph wind after 10" of rain.

No failures except the diseased ones far from the home.

The ones near the house can protect you from the ones farther from the house.

 

[sawn_penn]

I've got five 70' trees on a quarter acre city block. Might one of them fall, yep. Would I cut them down? Are you kidding? I like the trees, and I pay my insurance just in case something happens.

I've seen lots of tree vs house incidents. Whenever there was a big storm, I'd spend my nights visiting them.

Things I've noticed:

Most trees don't fall on houses. We did more "tree across road" jobs than "tree vs house" jobs.

Many of the trees that did hit houses did remarkably little damage to the house.

We did a lot more storm damage work (blown off roofs, etc) in suburbs with hardly any trees than suburbs with lots of trees.


Around here, a policy that covers all risks to the structure except termites and flooding (by standing water, I live on a hill) runs to about $1 per $1000 of construction costs. $400,000 to build the house, $400/year to cover it against all risks including getting hit by a tree. The insurance guys vote with their wallet. They don't think my house is going to get squashed by a tree.

 

[BlueRidgeMark]

The insurance guys vote with their wallet. They don't think my house is going to get squashed by a tree.

Yep. Follow the money. For all the bad-mouthing that we do about the insurance industry, they DO know how to protect themselves. (That's why we bad-mouth them! ) They have REAMS of data from which to estimate risks - it's the CORE of their business. If they think the risk is small, buddy, the risk is SMALL.

Does this guarantee that you'll never get hit by a tree? No, of course not, it's about probabilities. You assess the risk of it happening, and the COST of it happening (which includes possible injury or death), and you make a reasonable decision.

Continuing to live in a house where the risk is so high that leaving every time the wind blows is reasonable, is NOT reasonable.

OR....

The risk really isn't that high, and it's the leaving when the wind blows that is not reasonable.

 

[treeseer]

... make a reasonable decision.

Continuing to live in a house where the risk is so high that leaving every time the wind blows is reasonable, is NOT reasonable.

OR....

The risk really isn't that high, and it's the leaving when the wind blows that is not reasonable.

To find out, hire a qualified independent arborist to look at your site.

Worry less, Live Longer.