Penta Wood Treatment versus New Approaches to Log Preservatives
From the 1950’s to the 1980’s, Penta (or pentachlorphenal and creosote) was a useful preservative for woods. However, it was illegalized in the 1980’s due to known toxicity. Here in the Midwest many log homes have had this chemical applied to the logs through the years. Today many of these log homes are experiencing black discolouration because the effect of the Penta is wearing out. Penta works by preserving the outer 1 to two inches layer of the wood and if a rot occurs it will only take place in the deeper sections of the logs.
A log home treated with Penta in the past will most likely to have black spots on some sections in the logs. This black discoloration can be a cause of foreign elements present in changing weather conditions.
It is sad to say that today the Penta is not an effective means anymore for wood preservation because it has become vulnerable to many elements. The most recent exterior stains act in more amazing ways than the Penta. While it is true that the chemical reactions of the Penta can prevent the rot from holding onto the wood too much, modern stains of this generation ultimately works by preventing moisture to sink in and cause decay.
One very important step in controlling the moisture on wood is surface preparation. Those log homes that have been treated with pent it is vital to remove the old preservative first. This makes the outer surface ready for a new coat of preservative which will protect the log surface much better from harmful elements in the environment. For such cases, experts usually recommend blasting the surface with sand, glass, or cob in removing the old finish. This process of log home repair basically cleans up the wood to prepare the surface for a new coat of protective stain.
After blasting and before proceeding with staining, a preservative that contains borate is importantly applied and it works naturally than the Penta. The pH level of the logs is raised in such a way that it will only need a fewer percentage moisture points before rotting will start. Afterwards, a high quality exterior stain is coated on the log surface. The inhibition of UV rays, protection and the ability to breathe are the most important factors when looking for a good quality wood stain.
A log home applied with borates and stain is very impressive to anyone’s eyes and also retain its appearance and shape much longer.