Ever wondered why timber repairs made to rotten parts of old window frames never last as long as the timber from which the original windows were made?
To answer the question we need to look back into our history to the time when softwoods started to be substituted for the usual choice of timber, mostly Oak, in the construction of window frames.
It is believed that it was around the end of the 1600 hundreds that softwood began to be imported into this country from the Baltic countries and by the mid 1700s it was big business.
Softwood timber at that time was graded differently and with more grades that we find in our modern day. Most of the prime softwood came in from northern Russia and was sold as Archangel joinery grade 1 & 2. Due to the fact that grade 1 was all heartwood, centre of the tree, which meant that it would be very durable and therefore suitable for use in the making of window and door frames fit for high class buildings. Grade 2 was also heartwood but a small amount of sapwood, outer part of the tree below the bark, was permissable as it would be cut away during the planning and moulding process.
Softwoods graded class 3 were used in staircase work, skirting and architrave. Grade 4 would be used for floor boards and grades 5 & 6 for structural timbers i.e. ceiling joists and roof rafters. Interestingly only Russia supplied 6 grades of softwood whereas Finland And Norway offered just 5 grades.
Bring us up to modern day joinery grade softwoods we find impotant differences. Most of the softwood that we use these days is graded as unsorted and likely equivelant to the old 4 & 5 grades. Also of note is the fact that these days a lot of timber we use is rapidly grown in plantations, mainly Sweden, which means it contains more sapwood which unlike heartwood is not durable and therefore prone to rot quicker.
We hope you found this article informative and some way towards explaining why softwood repairs carried out to old windows do not last as well as the original timber.
If you would like to know how to make a windor repair last better or would like a quote to have a window repaired or replaced then feel free to give us a call on 01730 828440.