Inspection number 20
Today’s inspection took me to the northern part of Haliburton County, these are always inspections that I enjoy, more just the anticipation of what I will see as I drive up the laneway. The snow is heavy in this area so inspections this time of year always carry a heightened risk factor with them. In most cases there is very little that I can see of the roofing material, so the exercise is to flag areas that are typically problematic and be particularly diligent about looking for repairs or fresh paint to the ceilings and upper walls. In this case the ice damming was extensive on the metal roof; however no indicators were present that would suggest that it has reached the point of causing any interior damage. I believe this to be due to the fact that the eaves projection beyond the walls was at least twice what the normal distance usually is. This was a good design on the builder’s part.
This particular home was of log construction. This is an area of home construction that I find varies greatly when it comes to quality of workmanship. Not all builders are cut out to do log construction.
Log construction has many variations the earliest form would have been, most likely the round log scribed system. Very little hardware if any was needed with this style of log construction. That is not to say that it was not necessary to have skilled carpenters doing the work, on the contrary these early builders had to have their wits about them. Not only was it important that each log was carefully sized and cut but they had to take into consideration how much shrinkage they were going to have, and build in allowances to enable window and doors to still operate freely even after as much as 10inches of log shrinkage had taken place. These early builders were very savvy in understanding the importance of surface and roof drainage. Overhead projection of the roof line well beyond the corners of the building would be the key to longevity. The butt end of any log is it point of greatest vulnerability. In looking at log structure the two most common problems that I find is outside corner rot and rot at the logs that are at grade level. The decay of the log is just the beginning, once we have wet rotting wood that opens the door for the an array of wood boring insects the two that are most prominent are the Powder Post Beatle and our old friend the carpenter ant. Once infested the log home will quickly succumb to the ravaging of these little buggers.
From this point in time to the present the evolution of the log home, like everything else has grown exponentially, new techniques, new systems, prefabricated factory built homes and the list goes on. The log construction that I looked at today was and is the most simplistic of all log construction and even with that it is (so far) standing the test of time. At a young 22 years of age things were weathering pretty well. The log style in this home is a simple lap joint on the corners with (I assume) a dowel driven through to maintain alignment of the outside corners. No scribing here, no carful fitting just a timber (5x5 squared hemlock logs) stacked on top of one another. This style of construction leaves a gap between each log which in turn is filled with “chinking”. In the early days chinking was a combination of mud and grasses that were mixed into a paste and then forced by hand into the voids between the logs. Chinking has seen a steady evolution from there, the next product was mortar and then a bitumen (various dark mixtures of hydrocarbons) product, and finally the product of choice today is a synthetic mixture that is commonly referred to as “pema-chink”. Perma-chink is a very thinly applied highly flexible product that is placed over a backer rod( foam dowel) or a high density Styrofoam. The Home that I was looking at had used the bitumen product which, with age and weathering had receded back inside the log by and easy inch and a half. This can certainly start to cause problems of water infiltration and wet wood and that means rot and insects. The good news for my client was that it had not evolved to that point yet.
Major Concern: exterior log repair. My client felt that this was manageable and moved ahead with the purchase of his cottage.
Hey, it has been great having you along for the ride
See you next time