Log Cabin Insulation

Advice on insulation for your Log Cabin Floor and Roof. Having taken time to consider the benefits of a thicker wall cabin and double-glazed windows there are ways to further improve your building with roof and floor insulation.

Insulating Your Log Cabin: Floor and Roof Tips and Tricks


44mm tanalised timber foundation beams are supplied with every building we supply. With the addition of an insulation floor pack from the local builders merchant at 40/50mm deep, cut to fit between the beams will provide good insulation before the floor is finally laid down.


This can be more difficult to achieve as the insulation is normally fitted externally. Therefore, we would recommend you talk with one of our Log Cabin Expert’s before attempting to insulate your new log cabin roof.

Timber Kit Buildings has many years’ experience in building log cabins, and we would welcome your questions on how to best achieve a good insulation for your new timber building.  For free advice call us or use the Contact Us form to send an email.


If we were fitting cabins, especially one of our thicker wall log cabins such as 40mm upwards, we would be strongly urging you to insulate at the least the floor of your new log cabin. We would also try to recommend you to insulate the roof as well.

A lot of heat is lost from the floor and it’s cold rising up and of course loads is lost through the roof. Ideally we want these areas insulated and to the same or similar as the wall thickness.

We offer optional ‘insulation kits’ with our products however you can purchase these from your local supplier if you prefer..

Simple guide on how to insulate your roof and floor of your new log cabin.

Have you considered a DPM? A damp proof membrane either within your base or on top of it. It’s well worth it and prevents any damp coming up and into your building.Insulation board is placed within the bearers

Now simply lay the floor boards as normal.

Another method is to not bother with the floor pack and to fill the inner area of the cabin with the insulation boards. On top of that you use far cheaper OSB sheets or chipboard flooring, this is especially relevant if you are later putting down carpet as OSB is certainly cheaper than our nice T&G pine.

Obviously you’ll need to work out how much board you need with a simple calculation of length x breadth to find the square meter and order the equivalent from your local builders merchant.

insulating a roofThe roof is a little trickier to do and takes a little more work. Before you start you need to decide what thickness of insulation board to use. 44mm, the same as the floor is very convenient and often used. You could also go up to 70mm to gain the same R value.

Work out how much you need by calculating one side of the roof area and times it by two. As well as the insulation boards you will also need to order longer clout nails. These need to be long enough to go through the final roof surface, insulation and into the roof timber boards. If you’re using 50mm insulation then order 65mm nails for the flats of the roof and 70mm clout nails for the ridges.

Lay the boards so they are flush with the leading edge. Bare in mind this is going to be exposed so consider how you’re going to cover it.

You can also cover this portion later with additional timber but it is worth considering it at this point. You may need to source locally the additional trim timber.

Now lay one layer of insulation boards and fix into place using one clout nail in each corner and one in the center. You can then felt or shingle it up to that first board. Don’t be tempted to do the whole roof with the insulation as you will eventually have to get on the roof to tile or felt it and with the whole roof done it can be very slippery.

Once a board is complete with tiles or felt move on to the next and carry on adding boards and tiles until you reach the top.

The last consideration is the bargeboards to the front and back. You can either move the supplied one up or double up the barge boards as below, again you may need to source this additional timber locally:

The same principle also applied to hipped, octagonal and hexagonal roof. The only slight difference is that you will finish the corners of the ridges slightly differently where by you will cut them flush with the end of the roof boards. You will then cut a fillet to fill in the ‘v’ that naturally forms.

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