Measurements of Log Cabins

Log Cabins – The Seven Dimensions

I have known some potential customers to have some confusion when referring to measurements of log cabins and this post will help to make it clearer, also, if you are looking at other suppliers generally they will use the same ones so this may help when looking at other options as well.

Please note though I have found a couple of UK companies measure from the roof overhang so it is worth clarifying this point if you are buying elsewhere.

There are Seven measurements of log cabins that you will be interested in and these dimensions are referred to as:

  • Log
  • Interlock
  • Foot print
  • Roof
  • Canopy
  • Log Thickness
  • Internal

I am going to use the example of a 4m x 4m log cabin.`

Log Dimensions

Our dimensions refer to the fullest extent of the wall logs, for instance this will be the configuration of a listed 4m x 4m log cabin such as the >Jari 4x4m Log Cabin

4m x 4m log cabin. The log dimensions are to the furthest extent of the logs that form the main building excluding canopies or roof overhangs. This will include a veranda.

The log dimension does not include any roof overhangs or canopy dimensions. This is the measurement of the base log that forms part of the ground plan of the building, this will not include the canopy but will include the veranda if one is featured.

Corner Interlock

Due to the construction of a log cabin we must have a corner interlocking joint. This has to be set away from the end of the log and sufficiently far enough to maintain strength and aesthetics. On most occasions this is 100mm but some cabins we do make it very slightly smaller, generally with the 19mm buildings and some corner building to keep internal space to a maximum. Check the product pages for this.

For this post and to enable understanding, and as 98% of our buildings are 100mm, we will stick with this example. This is the interlock dimension:


Interlock dimension – This is the measurement from the outside of the log to the outside face of the base log which forms the footprint.

Footprint of a log cabin

This is quite important especially when you are looking at your base. This refers to the very minimum your base can be and is the measurement required to support your wall logs properly. A base can be bigger than this but never smaller. The footprint is calculated by:

Main Base Log (4000mm) – (Interlock (100mm) x 2) = Footprint

This is the footprint dimension:

Footprint dimension

Footprint dimension – this is very important as it is the minimum dimension required for your base.

Log Cabin Roof Dimensions

This is the dimension of the roof and normally when we refer to it when asked, we state the ‘roof overhang’. This is generally 200mm – 300mm to the rear and sides on most log cabins.

If this is critical to you due to close proximity of a boundary you can happily cut this down to the full og dimensions. The roof overhang is there to protect the side walls, windows and doors from ingress of the weather. This measurement should be taken into consideration when calculating insulation or roofing material needed. Do not cut this down further than the log dimension.

Please Note: One or two suppliers list this as the cabin dimension. If you do not check you may end up with a log cabin smaller than you had expected.

Log cabin roof 'overhang' dimensions.

Log cabin roof ‘overhang’ dimensions. This is the amount that the roof boards overhang at the sides and to the rear of the main log cabin wall logs.

Canopy of a Log Cabin Dimensions

The canopy is always listed with us as an extra dimension, for instance our Stian 58mm 4m x 4m log cabin is listed as 4m x 4m but does have a 1.40m canopy. This is in addition to the mentioned 4m x 4m log dimension.

The canopy measurement is an additional measurement to the main log.

The canopy measurement is an additional measurement to the main log dimension.

Log Thickness

Log cabins that we, and others offer come in a variety of thicknesses. Please see our main categories which list these thicknesses: Tuin Log Cabins A log thickness you decide upon represents its intended use, for instance in my opinion the thicknesses can be classified as:

19mm log cabins are a storage solution to replace a shed far more economically and with a higher strength and longevity than a panelled shed.

28mm log cabins are a leisure building for use as a summerhouse or to enjoy the warmer months, it is not really for all year around use without adaptation.

34mm – 45mm log cabins are more as a studio and benefits from additional strength and heavy duty usage, these can also be added to with insulation and may work out very economical with some adaptation.

58mm cabins are for offices and accommodation and start to become a serious building for all year around uses with the addition of insulation in the roof and floor

The 70mm log cabins and above are for multiple rooms, strength and insulation properties.

Log cabin wall thickness dimension

Log cabin wall thickness dimension – this is dependant on you and your requirements from you log cabin

Internal Log Cabin Dimensions

This, against the footprint dimension, is probably the most important dimension you are interested in. This represents the amount of room you have within your log cabin and is made up of the following equation in this 4m x 4m example:

Footprint = Main Base Log (4000mm) – Interlock (100mm)

Internal Dimension = Footprint – (Log thickness x 2)


Internal Dimensions = (Log – Interlock) – Thickness

This is a log cabins internal dimension:

A log cabins internal dimension

So, if we look at the following examples the internal dimensions are:

Measurements of Log Cabins Summary

As I have mentioned above, these are the measurements of log cabins, others will do the same but it is a good idea to check with your supplier if you are not buying one of our log cabins

Twisted Log Complaint

I had a complaint recently about a twisted log at the start of a customers log cabin build. I was sent these two pictures and a complaint email:

A wall log had twisted slightly.

A wall log had twisted slightly.

Twist in a log cabin wall log

Twist in a log cabin wall log which caused the lower log to lift up when unsecured.

His main complaint were the twisted logs. I tried explaining that wood does twist sometimes, it cannot be helped by it’s very nature. This can sometimes happen especially when a cabin has been unpacked and then left for a while before install. It can also happen just with the heat of the sun on it causing the wood to dry losing moisture quickly on one side. Rarely though is it a problem and it is very easy to overcome.

His second complaint was that the joints were too tight and that he didn’t have a hammer to hit the logs in. I explained that, yes, the joints are tight, that is part of why you would buy a log cabin from us: Please see Moisture Content in Log Cabins and also: Wind and watertight connections

I’m normally very good at talking through fit problems with customers but on this occasion I failed, so my colleague also spoke to him and failed. We sent pictures on how to overcome his issues but none of it was enough to solve the problem for him.

We also found out that the customer did not have the necessary tools to actually carry out the install or overcome the twisted log problem anyway. Also he explained that he was not aware of what is required in installing a log cabin and we should have let him know.

All my blogs have been in vain! None of it was referred to and I thought I had done so well in giving as much information as possible.

Mr B was one of a handful of customers I have had this year who insisted these were grounds for a big complaint and that it could not be installed.

I really don’t like complaints, especially when there’s absolutely nothing wrong. It’s also very costly for us as well and I needed to understand why a customer does not understand the install and why it become so daunting and complaints raised. I realised that no amount of explaining or pictures or email was going to solve this so I arranged a site visit with Mr B.

On meeting Mr B I was able to spend a long time with him asking about his impressions, why he didn’t realise fitting was a little more than slotting together and why he wasn’t aware of the tools needed. It came across that we’re not getting the information out there or fast enough on the product pages or post purchase emails. Mr B explained that he thought it would just slot together and would worry about installation when the cabin arrived. With the two twisted logs and the fact that the logs do not simply fall into each other the whole task became too daunting and he simply said he couldn’t / wouldn’t do it and it was a complaint, defective, fault etc.

Armed with this information we are going to have a little redesign of the site and will try to make information quicker to access. Mr B explained that he is very visual, pictures not words are needed. The only option is full videos and this is what I am now doing and will be doing all over the winter to try and help more, not just with log cabins but as much of the product range as I can.

With my sparkly new video camera I have tried to address all of Mr B’s problems and concerns which I hope will help future customers with the same problems

We took the partial log cabin installation apart and reset everything and started again from scratch.

These are the videos that arose from our conversations and his install of a ‘faulty’ log cabin, these are going to form the basis of a whole series on log cabins and their installation of several different types we supply.

Tools that are needed for a log cabin install

Installation of a Log Cabin – Full install overview

One of the biggest things that came out of our conversation was that Mr B had not expected the joints to be tight or that it would require any force to go together, he said he had ‘Expected a little resistance’. Some suppliers cabin will fall together with no effort at all, it might be a good thing when you’re installing but a bugger when it rains hard a few months later.

This log cabin install video is pretty long at 20 minutes but I needed to address every aspect of the install as Mr B wants everything spelt out, I have tried to do this for this particular cabin. Much of this applies to any of our apex log cabins and the same principles can be applied to our hipped roof log cabins.

A lot of customers will complain about instructions as well but most of a log cabin install is a practical ability and an ability to simply read a set of plans, an understanding of timber and it’s foibles does of course also help. I hope this video gets across exactly what is required. I like to think that if Mr B had seen these then we would not have had the complaint in the first place.

You may be also interested in other customers buildings posts and thoughts: