Adding a Window

Another Window?

Imagine you’ve built your log cabin and you find you need more light, or perhaps you already know you will need another window.

An additional large window has been added to the rear of this standard Rick 40mm Log cabin.

Or maybe you cannot block out that amazing scenery you have from your garden.

an extra window has been added to the rear wall of this Jutka, Gazebo, log cabin combination building.

If you do decide you would like another window Tuin do offer these, they’re a generic window of various sizes and can be fitted to any manufactures log cabin of thicknesses from 28mm up to 70mm:

When to Install an extra window

If you’ve already decided you would like an addtional window to that which comes as standard with your building you will probably order it at the same time as your building. You’ve then got to decide whether you are going to install it at the same time or afterwards, neither really matters, but my  preference is to always install it following the whole install. I like this way because:

  • You can be sure the main building has gone together correctly.
  • You will not void any guarantee.
  • You can be 100% certain of the positioning.
  • You avoid making mistakes in cutting logs.
  • You can be sure you are not going to structurally effect the log cabin.

Of course you can install it as you go but you run higher risks of a mess up, of which I have done in my early days fitting log cabins – namely cutting the logs wrong which does end in tears when there is no spare logs.

Generic Window Parts

There are several ways windows are made for log cabins and invariably they all follow the same pattern; they are a window frame with fascias applied to create a U section that the wall logs will sit in.

Remember it is important that the windows or doors are NOT fixed to the logs in any way to allow for expansion and contraction.

Below is an old Generic window I found in the workshop which I’ll use as a demonstration on how I fit the window.

Various parts that make up the generic window.

These windows are made up three components:

  • Window Frame.
  • Spacer Pieces according the width of wall log.
  • Window facias.

If we look at the spacers / battens you will see there is a paper label showing you the measurements for various log thicknesses.

Spacers which are marked and will be cut down to match the log thickness you have in your building.

Of course if the paper is not there, lost or got wet or even if your log thickness is not shown then you can easily measure this. If you are cutting to your own size it is best to make is 2 – 3mm larger. For instance; a 40mm thick wall log would have a spacer measurement of 42 – 43mm in width.

It might help to layout the parts so you can see exactly what you have.

Parts of the window. You should have two top, four side and two bottom fascias. As well as the spacers or adjustable battens whichever term you prefer.

Fitting the Generic Window

Before you start, trim down the spacers to match the thickness of your log cabin either by using the mark guide or measuring yourself. We are going to fit this window into a 58mm log cabin at our show site.

58mm thick wall log.

Start by marking the spacer for your size of wall log

Cut the spacer down using a handsaw or if you have it use a circular saw or jigsaw.

Once you have your spacers to size you can then fix them to the window frame.

Spacers have been fitted on each of the wides of the window frame.

You will of course need four spacers that go on each side of the window frame. You can fix these however you would like to, some fitters will use nails but personally I like to use screws as I think it gives a better fit, it’s easier to take apart and is generally stronger. The choice of fixing is yours at this point.

I prefer to use screws to fit the spacers but it is up to you at this point.

Cutting a hole in your Log Cabin

This next bit can be a bit tense and I must admit it still makes me a bit nervous in case I mess it up.

Before we start measuring or cutting holes we need to find the best place for our window. There’s a couple of rules to follow:

  • Do not cut any closer than 200mm to the interlocking corner of the cabin.
  • Do not cut any closer than 200mm to the side of another window.
  • Ideally start or finish your cut on a full log.
  • Ideally leave at least two clear logs above the window to maintane integrity of the building.
  • Make your own judgement of the integrity of the building once the hole is cut, if you need advice for a tricky placement please contact the main office or leave a message on this page and we’ll be pleased to help.

You can measure the window and transcribe those measurement onto the walls which is what I think a lot of people do. You would start at the centre point and measure out either side both top and bottom and then mark the lines.

Personally I still don’t trust myself or a tape measure and hold the actual window frame (including attached spacers) to the wall and mark around it with a pencil / pen. That way I can be sure my eyes haven’t gone wonky or the tape measure has stretched or shrunk.

Either mark out where you are going to cut the window by taking measurements from the window frame or hold the actual window to the wall and draw around it.

One marked you need to consider what happens when your log cabin either expands or contract which it will do over the cycle of the seasons. For more details on this please see: Expansion and Contraction in Log Cabins.

As you will know it is necessary to leave an expansion, or, contraction gap above the window to cope with seasonal variations. The gap you make will be decided by the time of year you are installing:

  • Height of Summer: The wood will be at its smallest as a lot of moisture will have escaped. Therefore only a small gap of 10 – 15mm maybe necessary as the building is only likely to expand more as Autumn and Winter arrive.
  • Depths of Winter: The wood will be at its largest size as it will have absorbed a lot of moisture from the surrounding air. Therefore a gap of 20 – 30mm maybe necessary as the building is only likely to contract as the Spring and Summer arrive.

As the logs expand marginally length ways you only really need a gap of around 5 – 10mm either side, again depending on the time of year you are installing.

I prefer to be on the right side of caution and will perhaps make the expansion gap slightly smaller. I will then advise the customer to check behind the fascias as the season changes over the first year to make sure a gap is still present of at least 5mm in the depth of winter. If it is not it is easy to remove the window and take out a little more to allow for the gap.

Making our marks to allow for expansion and contraction of the logs around the window frame.

Once you made your marks, double and triple checked then we can cut the wall logs. A circular saw make sit easy work but you can of course use a hand saw.

Cutting the hole is easier with a circular saw but you can also use a jigsaw or a hand saw.

A complete window hole cut. Do not worry if you are not 100% straight in your cut as any slight deviations will be hidden behind the fascia.

You can offer up the window to check for fitment.

Final Fitting of the Generic Window

You can now fit the fascias on the outside of the window, again, like the spacers you can either screw or nail them onto the frame. I personally think screws are far better but it is up to you.

Fit the fascia to the outside of the window frame onto the spacers.

When you are working with wood it is always highly advisable to pilot hole anything you are going to be screwing or nailing.

Always use a pilot hole when screwing or nailing one piece of wood to another.

Once all four of the outside fascia has been fitted you can then place the window into the hole. In the next picture we have done this from the outside. Notice one single screw used in the centre of the top fascia, this is to loosely secure the window so it can be completed from the inside single handedly. It is of course better if you have someone holding it for you.

Note the screw will be removed once the window is installed.

Complete window fitted from the outside of the log cabin, loosely held in place by one screw at the top to make it easier to fit. The screw is of course later removed.

The fascias are fitted to the inside and the ‘helping screw’ outside is removed and the window is complete.

There we have the completed window!

A Few Window Notes:

Fitting a window is not too hard at all, just consider you expansion and contraction gaps, also the old saying of ‘measure twice cut once’ is very relevant.

Over the first year as the seasons change, periodically check your gap above the window, you can easily remove the top fascia to check behind it.

If security is a concern you can:

  • Countersink your screws and use wood filler mixed with sawdust to hide your screws on the outside fascia.
  • You can use Philips head screws and once installed drill the head so it can no longer be used.
  • Use security screws.

7 thoughts on “Adding a Window

  1. Hi Richard, I’m about to purchase a palma 34mm log cabin with an extra single solid door that I will have opening internally, I understand this will then need a liitle adaption to keep watertight. Once installed I will be purchasing another identical cabin, with another internally opening door, this will sit flush with the first with space for guttering between the two Cabins. I am planning on using extra timber and connectors to bridge the front and rear space between the two. I will essentially of joined the two Cabins. I would like the second cabin to only be accessible from the internal door of the first, again using H connectors and extra timber I plan to wall up where the front double door would be. Any advice would be greatly appreciated
    Gregor

  2. Great advice. We are coming to the end of our build of a Big Lauren Clockhouse, which we have installed a hottub and now realise that a set of bi-fold doors would be an excellent addition rather than the 4 Windows. Any advice on this please? the weight of the roof appears to be taken by the first purlin so structurally the integrity of the cabin looks ok. Would you use aluminium doors?
    Gavin Rock
    Haverhill

    • Bi-folding doors would look great and the same principle will apply regarding cutting the hole and leaving expansion and contraction gaps. An aluminium frame would be a good idea as bi folding timber doors can drop over time. You could also consider sliding glass doors similar to these:
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