My first post here, been reading your forum for quite some time and wanted to thank for all of you contribute to this forum as it helps a lot of amateur's such myself towards getting something built. Around 18 months ago I pretty much knew nothing about building, then we bought our 1st house in November 2020 and spent full year completely renovating it from top to bottom which I believe has now moved me to amateur DIY level
What I am looking for now I could not find on the forum, therefore created new topic and hopefully somebody will be able to help.
Basically we are planning to build another garden building for sauna and gym, already sorted paperwork with council etc and now left last steps before finally ordering stuff, doing foundation and starting the build. Due to the shape of our building (limited due to position within the garden) there is no ready to build kits for me, so we will have to do the whole build ourselves. All this time I had my mind set on using SIPS for floors, walls and ceilings, however just recently I looked into the price of cladding and was pretty shocked - easily looking at around £30sq metre just for external cladding, whether it would be composite or wooden option, as you probably know all comes up very expensive, as we want to have wood effect inside internal cladding would not be cheap either, therefore with cost of SIPS and internal and external cladding, walls already hovering around £100sq metre which is definitely more than I anticipated.
Due to high cost of cladding, I then went looking into log cabins, again no kit for us due to shape, but can order logs separately, however also price comes around £100sq metre for medium thickness 45mm logs.
Then looked into timber, c16/c24 rated timber sized 47mm/150mm comes at around £40sv metre and could be used same as logs to build the wall, right?
And now finally the question - was looking into thicker timber and found timber sleepers that are 100mm/200mm in size and work out to be under £50sq metre - and here is my question - is there any reason why I could not use sleepers for the walls of my garden building? I would stand them up so it would sit 200mm height and 100mm thick - this way the walls would be 100mm thick and provide more than enough insulation and actually much thicker than other log or timber options, so it would be like building with thick timber logs. Or is there something that I am missing here? We could lay them in pattern as per attached to ensure they hold in place. The only thing that I can think of is if sleepers are not perfectly straight when placing them on each other we might have some gaps between the logs or the gaps could be appear after from the movement of wood, but apart from that I cannot think as to why they could not be used? I want wood effect on both inside and outside of the building, so with right wood treatment that would be job done without additional cladding etc. For floors and ceiling I would probably still use Sips. So is, this completely bonkers idea or actually doable?
Thank you in advance!