Log workshop too low ?

[swampydrill]

I have a large cemented base for which i have ordered a 4.5m x 2.5m log workshop. I would say that the concrete base is not all that level but not overly bad. I have realised that the workshop comes with bearers that are actually part of the floor base, unlike my shed, which has a floor base on top of 3" bearers. I am a bit worried that as the floor is not completely level, there may be issues in both erecting the workshop and water getting in later through any low spots.
If i mark out the area where the workshop will fit, make a level wooden frame from 1 1/2" timber, fill it with self levelling concrete / compound, do you think that would suffice ?
Could also lay some slabs down underneath or could build it best as can and then silicon around the base ?

 

[theprinceofdarkness]

The whole structure will be supported on the bearers, which in turn need a decent support every couple of feet or so. This can easily be a splodge of mortar about 3" square. The mortar and base will need a piece of DPC inserting (roofing felt/bit of thick plastic bag). It is best if all the wood can be kept off the base or splodges, so the bottom of the wooden bearers do not sit in a film of water.
You do not say how far from being flat the base is - .5"? .1", 1"? Also there must not have any twist in it. The floor will take up a twist but the walls won't, there will be gaps at the corners.
Frank

 

[tomfe]

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[swampydrill]

I finally move the old shed off the base today and had a good measure up of the are the log workshop is going. The workshop is 4.5m x 2.5m, over the width of the area there is no more than 1/2" height difference in the base, over the length it is about 1/4" although there are a couple of dips in places up to 1/2" which i guess i can use some packers to help support it. Will look to build the base and then black jack the underside to help protect it, will take some time on the base to make sure is solid.