# What is the maximum depth below grade for termite activity?



## iLikeDirt (Apr 27, 2014)

How far below the surface do most non-formosan subterranean termites typically tunnel? 4 inches? 12 inches? 3 feet?


----------



## joecaption (Nov 30, 2011)

All depends on moisture content of the soil and what there going after.
Old rotten tree roots and there going to keep going until it's gone.
Why you asking? 
Almost always a real reason for asking a question.


----------



## iLikeDirt (Apr 27, 2014)

joecaption said:


> All depends on moisture content of the soil and what there going after.
> Old rotten tree roots and there going to keep going until it's gone.
> Why you asking?
> Almost always a real reason for asking a question.


Heh, true!

The reason is that in addition to chemical protection, I am interested in adding a physical termite barrier around my slab-on-grade house. I want to know what the practical maximum depth would be for such a barrier to be effective. If the answer is 6 feet, for example, then I won't do it, since the effort would be too great. But if the answer is 1 foot or 6 inches, there I think it is worth it for an extra layer of protection.

The house has been attacked by termites before, and successfully treated chemically. I want to maximize the number of defensive layers rather than relying entirely on a single chemical one which dissipates over time and has to be paid for over and over again.

I live in a desert with an average annual rainfall of about 9", so the soil is pretty dry.


----------



## ddawg16 (Aug 15, 2011)

Dirt....you have the same termites we do here in S California.

Your biggest threat is not the ground but from swarms.

Are you on slab or crawl space?

Treating the ground is not going to do much for you.


----------



## iLikeDirt (Apr 27, 2014)

ddawg16 said:


> Dirt....you have the same termites we do here in S California.
> 
> Your biggest threat is not the ground but from swarms.
> 
> ...


Slab on grade. The house was previously treated in the ground; in fact I can see the filled-in holes in the footing around the perimeter of the house. This treatment was evidently effective because I have also found termite damage to lumber in the walls, but no living termites in the mud tubes there. I can also see the living subterranean termites eagerly eating a piece of lumber I recently poisoned and left in the yard far away from the house. So they're there. No swarms so far though.


----------

