Timber Frames – Packing
An issue with timber frames is making sure that the frame is bedded securely on the floor slab. . . . You don’t want movement of the frame when the house is completed!
Flatness of the Slab
You may think the building slab looks flat but in practice very few slabs are perfectly level.
The Guide to Standards and Tolerances states “Generally the floor shall be within + or- 10mm of the finished floor level in any room and within +or- 5mm in a 3m length.”
So when the frame is put on the floor it could look something like the exaggerated sketch below.
Making Sure The Frame Is Stable
The key issue is to make sure that the frame is fully supported under the stud positions otherwise the studs can move vertically.
That means that packing will need to be fixed under the bottom plate at the locations shown by the red arrows above.
Packing can be made from hardboard, MDF, Plywood, metal, formica, or specialised plastic packers (sometimes called shims).
It is important that the packers should be secure and non compressible.
They should also not project beyond the bottom plate, otherwise they may affect the later secure fastening of plasterboard and skirting boards.
See Structural Frame for more posts
Thanks for posting! I’m helping my dad out with building the timber frame for their new house. We’ve been having trouble getting the slab to look level. I’m glad that you pointed out that building slabs don’t need to look perfectly level. I’ll show this to my dad so that he can see the sketch for us to know how to make sure that the frames that we’re building are stable enough.