What should I do for a damaged tree?

In the process of excavating a foundation hole for a building, the excavators have damaged a couple of oak trees, tearing off pieces of bark. My husband wants to put some kind of sealant on; I thought I remembered reading that sealant shouldn't be used. I found a few websites recommending duct-taping the piece of bark back on but I think those may have been more for younger, thinner-barked trees. What should I do for these trees??

Trim off any ragged edges around the debarked areas. You want it smooth to help the tree form a callous over the wound. New wood will roll in from the outside edges and eventually cover the barkless area. You're correct that sealants are no longer used. Sealants trap moisture behind them and allow a place for insects and rots to gain a foot hold. The best treatment is air and sun light. The trees will take care of themselves. An annual fertilizer feeding and ample watering will speed the process. Can you post any pictures? It would help to know the tree size and the amount of bark lost. I've never heard of the duct tape thing ( a suprise since my DH believes that it's the single answer to all of men's repair needs). It's not reccommended in any of the athoritative sources I've read. The University of Maine Cooperative Extension has a very nice fact sheet that covers a lot of tree maintenance issues including taking care of construction damaged trees. If you clink on the link below it will give you a lot of tree care information. Cooperative Extension is a free, nationwide source of horticulture information, admininstered state by state, through state universities. All the information given is based on university research. You can't go wrong using Cooperative Extension information. Step back from the tree and put down that roll of tape. ;)

http://www.extension.umn.edu/distribution/housingandclothing/DK6135.html#Treatment

I was surprised to see in the article that if bark on an oak tree is injured by construction activity in the early summer, they do recommend sealant w/ water-based paint or shellac to prevent oak wilt. But apparently it's only recommended for injury early in the summer. And the sealant is supposed to be applied immediately. For both the latter reasons, it appears no sealant remains the correct course of action.

Using latex paint to prevent Oak wilt is only effective if applied immediately. The beetle is attracted to the fresh injury for just the first three days. Sealants hinder the healing process, but it's better than a dead tree! Here the rule of thumb is don't prune your oaks before August 1. Some arborists won't prune oak before the first frost.

We had some major pruning done on our Oaks in late August three years ago. I made certain that the company had disinfected their tools too. They claimed they disinfected them daily through the season between jobs, no matter the species. You can't be too careful.