Concrete cabin base

[industryspark]

Advice on the best course of action would be appreciatted.

I have had a concrete slab installed in my garden onto which i will be instaling a log cabin.
Hardcore subbase, visquine sheet and then 5'' of concrete in the shuttering. The concrete level sits an inch above the lawn. The cabin will sit on bearers supplied with it.

As per the cabin manufacturers instructions the concrete base was made 100mm bigger than the cabin on each side/front/back. It seems scanning a few sites that this 100mm requirment isnt such a good idea?

Can anyone explain why and recommend a course of action i could take to minimise any future problems as i still have time before the cabin is delivered.

regards

 

[motorbiking]

I’d have put 100mm of polystyrene insulation in the base. But it’s too late now.

Is your concern about water ingress under the cabin?

you could put a DPM down and fold it up under bearers and add a skirting clad to cover.

 

[Nige F]

Probably because the 100mm might get some rain/splash on it which then could run under the cabin - I would (if you have time ) soak the bearers in wood preserver, even if they are tanalized. Make sure air can blow between them and fit a gutter to the roof

 

[industryspark]

My concern from what i have read on other sites is just that yes, water running onto and under the base and rotting the bearers.

I will be fitting a guttering to take the water away from the roof and even though the bearers are pressure treated, i will add a coating or two of preservative.

Would a damp proof membrane between the bearers and the concrete be a good idea or could it restrict air flow to the bearers?

Also i will be painting the cabin as it is untreated. I am wanting to stay with its natural spruce colour or very close. Can anyone suggest a brand of paint/treatment that will be suitable for the job?

Thanks for the input guys

 

[Mike13]

I put these over the DPC and under the bearer beams: https://www.tuin.co.uk/Composite-Profiled-Foundation-Beams.html it also allowed thicker insulation under the cabin floor.