Cutting a Tree

Cutting a tree

Surely its as simple as put it on and then cut out what you need? Cutting oak is a interesting and challenging problem at the same time. I have been to softwood mills, I have seen them programme a computer and tell the saw to cut on repeat. Unfortunately, with Oak we cannot do that. There are lots of variables that we have to take into account when cutting for the different uses we produce in fresh sawn oak. Knots, heart shake, shape, sap, rot and, in-bark all have an impact and not all are obvious from looking from the outside of a tree.

The first rule for oak is the further you go up a tree the larger and more common the knots are. For us the first 4-6m of a tree is relatively easy to deal with. This is the cleanest part of the tree with few to no knots and character. The tree at that height grows relatively straight, which makes it easy to handle. The majority of this section of the tree that we cut end up in two or four metre pieces and are cut to 35mm for Quercus fencing. They then weave it to make panels which grace homes throughout the country. Because of the section they use the timber needs to be virtually perfect any fault will result in the timber breaking when stress is put upon it. Cutting this relatively straight forward. Its clean and so the main problem is minimising the waste from the heart of the tree. This a crack that runs through the centre(although not dead straight). Generally the rule is the bigger the tree the bigger the heart. This means more waste. When cutting a beam which we do with the tree from 4m plus you would box the heart in the middle of the beam cutting out the waste, but it is different cutting 35mm plank. When cutting the butt of the tree (the first length), the effect can be minimised by tapering the cut to remove some of the heart. The bottom of the tree is wider than the top and he saw cut be adjusted so that an angle is put on the tree going into the saw. This allows us to get more useful timber.

As we move up the tree it becomes more of an educated guess on what you are going to find when cutting a tree. There are a number of things to look for a tree that can effect its use. For waney edge cladding you don’t want any large knots sticking out of the bark. The bark needs to be intact and looking healthy and it needs to be straight otherwise the variation on width is going to make the cladding look odd and impossible to work out coverage. Cutting this is relatively easy and involves cutting through and through the tree, turning it down on to the flat edge and repeat when the width gets too wide to try get a consistent width. This generally is when you get to the centre of the tree and normally involves turning the tree down three times.

When cutting beams, the outside of the tree isn’t so important. Knots get smaller as you get closer to the centre of the tree and so you have to take an educated guess on whether the knots will shrink quickly enough to be acceptable on a beam face. A ten by ten beam can have a bigger knot than a four by four beam and so that has an impact on the decision. The heart also plays a role. A big heart needs to go in a big beam otherwise there will be an unsightly crack along a face or two. If you are trying to cut multiple pieces out of a tree such as 4x4s you don’t want a big heart that may effect 4 or 5 of the pieces, whereas a tree with a little heart may only effect one or two or could be boxed.

Some trees have more sap than others. Sap is the first part of the beam to rot and so it needs to be minimised on a beam. Where you have a large amount of sap you get a lot of waste when cutting beams and so it may be better as cladding.

There are certain things that you have no control over. When crossing cutting a tree to length you can discover rot in the tree. If it shows in the middle of the tree it comes from a knot and it is important to discover where that know is as the area around the knot to the rotten heart isn’t likely to be good

for much other than sleepers. This is especially prevalent in English knot and is normally where the rotten branches haven’t been cut back and have been allowed to rot further into the tree.

Dead knots can appear in a seemingly good tree. This where the knot is soft and generally this is contained within the knot, but it can go in several inches deep. We try to cut them out, but sometimes its not possible. They can make a unique feature in a beam and don’t effect the structural integraty the of the piece. The other thing that can surprise us is in-bark. This where the tree has grown over something, for example a branch that didn’t reach the outside. There is often no warning and it can create a weakness in a beam that can cause it to be rejected.

The other issue we have is the straightness. The saw cuts on a straight line and so any deviation in the tree will result in a lot of the front and back or the middle being wasted and the attempted piece we are trying to cut not being realised. A lot of time is spent ensuring that the tree we select will be straight enough to get the beams we need. It is also the reason we do not cut trees over 4m at our mill as lining the trees on our saw can be tricky. For longer beams we work with partner mills.

Bench slats

The sun is shining (occasionally) and its time to think about the garden. We are the number one place to go for replacing slats in any garden bench or table. We produce a wide variety of sizes in Sapele and Oak to try to cover all requirements. We have bunched the most popular sizes in groups at discounted rates. Most orders are delivered within five working days and we have a good amount of good quality discounted seconds in the self selection centre. We can also produce bespoke slats to order. If we don’t offer the size you require on the website please email timber@yandles.co.uk or call 01935 822207 option 3 Mon-Friand we will be happy to quote.