we have a dunster house log cabin being delivered on Tuesday. We laid a concrete base last weekend, which was nice and level until the builder added a bevelled edge. Unfortunately the bearers sit right on the bevelled part, giving a slope of around 5mm. How can we resolve this? The builder doesn't think adding a thin layer of concrete or screed will stay under the pressure of the building. I was thinking of getting wider bearers and trying to pack the edge with plastic shims. Would this be strong enough? Alternately would I have to build up the whole area again with another inch of concrete, or pave the whole area.... We are at a loss...please help
5mm is not much tbh, could you not flatten it with a grinder? Sure someone will come up with other ideas, shims or metal plates would be an option, 5mm thin layer of leveling compound? WOI
Thanks for the reply. Not sure we can grind it level as that would mean reducing the level of the whole base (4x3m) by 5mm down to the lowest level. The supplied bearers are 32mm wide, meaning the whole bearer front and back, that is holding up the main supporting walls of 45mm timber, is on an angle. I was thinking of getting 150mm timbers to then add plastic shims under. I was wondering if the is something I could use to fill up the void.
Out of all the bearers the outer two will have a 5mm gap???? Are you sitting the bearers on a DPC if so double/triple it up on the outer two.
The bevelled edge means the 2 bearers taking the majority of the weight of the cabin are not level. But yes, I'll be using a dpc, so hopefully with that and Some plastic shims, everything will be ok
Do I understand right that the front and rear bearers will be angled due to the edge of the base being sloped? Those bearers take the full weight of the cabin so be sure to ensure they can't and won't move at all.
Yes, that is exactly the issue. I am trying to ascertain if I can simply pack the bearers. I am planning on using plastic shims and dpc to level the bearers, as well as increase the bearers from 32mm wide to 150mm wide.
Sounds like a right balls up, the base is compromised exactly where you need it level. I wonder if there's a way to put down a 2x2 timber sub frame but that would still leave the outer timbers without proper support. Or use those 150mm timbers and secure them at each end so they can't move forwards or backwards or tilt.
I would personally put back the delivery of the cabin (if possible) and explain the issue, maybe they have had customers who have had this issue before and they may have a solution. Any alterations you make to the structure yourself, I assume would void any guarantee on the building? You could then ask the builder what can be done to sort the base.
I've agreed to have the cabin delivered as we have next week off work to sort the issue out and build the cabin. Tge builder is standing by his work, saying that the slope is normal practice to ensure water runs away from the cabin. He is suggesting packing the bearers with DPC to level. I am going to speak to him later today.
Can you post a photo as Im now a bit confused exactly where it's out. It might be good practice to do this bevel but I'm thinking the fact portion is not wide enough. For a cabin the base should be flat and stop at the outside edge of the cabin walls...no bevel and no concrete protruding.
The company you buy the cabin from should give you dimensions for size of base so it fits exactly to the floor construction. Like Dr Bodgit has said, there shouldn't be any protruding base. If the builder has built the base to the floor dimensions and has beveled the edge, it's quite obvious that this will effect the timbers sitting flat and therefore although hos work is to standard it isn't fit for what you intend to use it for.
You would think so, but the supplier recommends a base whitch is 20cm larger than the bearers. This means at least 10cm is protruding all round the cabin. Again, this is one reason that the builder bevelled the edge to encourage rain water to run away from the building. This base being larger has come up on numerous other sites as a cause for concern. The builder is coming round on Tuesday to see the delivered cabin, and is going to bed the bearers on the dpc and mortar. I have suggesting laying slabs, but he is certain that this is not required.
Can't you use wider bearers so that more of the timber is sitting on the level section of concrete? Any photos available to gain a better idea?
See the project threads...this is why I'm not doing a concrete base for my cabin. It attracts water which then has no where to go and would not dry out. End result is rotten bearers.
In hindsight I would definitely use the plastic pad and adjustable risers. But I now have a great big lump of concrete, so just need to make the best of the situation. I have ordered wider timbers and the builder is coming round on Tuesday after the cabin has been delivered to bed the bearers onto a dpc and strong cement. Hopefully that will be good enough. I'll upload a photo of the existing base tomorrow
Cheers, found this for anyone interested : https://www.a1sheds.com/ecobase-fastfit-shed-base-from-459-12542-p.asp
Forums
Facebook
Twitter
You Tube
Instagram
Shop