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Termite Shields or Chemical Treatment?

Mel wants our opinion....


Do you have any documentation or opinion on the use of termite shields. Shields in addition to chemical pre treat.  Shields in lieu of pre treat.  Pre treat without shields.  Any information will be appreciated.

Thank you

Mel S.
Phoenix, AZ

So I wrote back with....

Hello, Mel:

Well, I don't know about "documentation," but I do have an opinion, of course.  As far as I'm concerned, every house should have a termite shield and every house should be pre-treated.  Pre-treatment for termites is so much cheaper and more effective than post construction treatment, it's a no-brainer.  You might think that exterminators "push" pre-treatment to just expand their business, but exterminators make FAR more money on post construction treatments.

The actual job of a physical termite shield is not, however, to "shield" a house from termites.  Alone, and after awhile, physical shields just don't work.  The termites find a way around them.  What they DO do, is to force termites out in the open, where they can be seen, instead of entering the bottom plate, unseen.

And there are many different kinds of shields.  Some are merely tar or roofing paper, laid on top of the topmost block.  They all fail, of course because of one feature - they are not continuous.  There's always a joint the termites can find.  Or the builder pierces them with nails.  Termites need only a 64th of an inch to gain entrance.  A really PROPER shield is constructed of either soft copper or stainless steel with double lap joints - I have only seen this a few times in actual practice. Naturally, along with a proper physical shield, the topmost block should be a cap block - one which is solid, offering no avenue to wooden plates.

In addition to a physical shield, pre-treatment of dirt fills and slab construction would increase protection from termites much further, especially under slabs.  Any slabs with heating vents or pipes cast into the slab should definitely be pre-treated. Termites will be attracted to heat from this type of slab, and without pre-treatment, the first round of termites will come pretty quickly.

Nice to hear from you.  Hope this helps.  Get back to me if you have more questions!


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