All too often do it yourself home owners, handymen and contractors alike build in the most preferable situations for subterranean termites. Wood to ground contact, covered expansion joints, stucco that goes below grade or any number of things can give termites hidden access. The work looks top notch and solid and everyone takes a step back to admire their work for a moment and then it is on to the next big job.
In some states there are pretreat laws for the soil when adding on to your home but what if you are using an existing slab? I’m not aware of any ordinance that requires treatment in this scenario and this is one major reason additions can become infested so quickly.
Recently I had a customer who has my termite service enclose a very large back screen porch. The
home is concrete block including the pillars for the porch area. Since it was screen in between the columns no treatment was originally necessary to the outside soil in these zones. Instead of more block however the walls where screen had been were now made with stucco over wood. To make matters worse the stucco went to and below the soil and mulch was piled up against it. With a cursory glance you couldn’t tell the difference between the block walls and frame so everything blended in very nicely.
On my annual inspection I picked up on this right away and let my client know of the conducive condition that had been created. Oddly, most customers don’t quite grasp the concept because visually the area looks so sturdy and impenetrable. One trick I do to illustrate this defect to an unbelieving homeowner is to have them watch and listen as I ‘knock’ along the wall. My knuckles make a solid ‘pap’ sound when I hit the block wall. ( I only rap a time or two, it hurts) But when I hit 
the frame section the whole sound changes to a weak hollow ‘donk’ sound that would probably echo if not for the insulation. This visual and audible demonstration at least alerts them to the hidden danger and soon after they begin to understand.
For these folks it was a quick 20 minute touch up job and it’s very unlikely they had any unseen subterranean visitors since my last visit but it could have been so much worse. With the wood so close to the ground and the stucco providing cover and holding moisture termites might have ravaged for years unnoticed. Unfortunately this happens to a lot of people whether they have termite protection on the rest of the house or not.
The other big problem is even if you have a termite contract you most likely voided it with the addition and no treatment or at least letting your termite company know. Some companies may send out a different tech each year and the new guy might not know your history and how the house was before. Good companies always send a graph or drawing to try and avoid this pitfall.
Just remember, somewhere in between picking colors and the type of carpet for your new room you need take time to exclude that hungry little termite. With this in mind you’ll be sure not to burn your money and you’ll be able to enjoy the fruits of your labor for a very long time, maybe even next to your brand new fireplace.
