How much does carpet + underlay compress?

[renMike]

I think I'm going to get the "it depends" answer but I thought I'd ask in case there is anyone more experienced than I in this matter.
I'm building a new desk over a carpet and underlay floor covering. The desk top is supported along the back and one end by battens on the wall leaving the other two sides unsupported. I'm going to attach a leg in the unsupported corner but will need to cut it to size. I can measure the floor to batten height but am concerned that over time the carpet and underlay will compress leaving my carefully measured and cut leg wobbling about.
Any thoughts?

 

[Swwils]

The leg should have an adjustable foot. If not you would just pack it as required.

Also, it depends.

 

[renMike]

It's a chunk of wood at the moment so doesn't have an adjustable foot. I'm going to cut it to length and so wouldn't want to pack it as I have the opportunity to get it right (maybe) now.

 

[foxhole]

Whatever length you cut it will be too short after the carpet and underlay compress with time. Easy enough to fit adjustable foot.

 

[renMike]

All cut now. Hope it stands the test of time.

 

[Mottie]

It compresses 0.87% of its total thickness per year for the first two years reducing to 0.23% per year for years three to seven and 0.09% for years eight to eleven. I have no data going back further than that. I hope this helps.

 

[renMike]

Thanks Mottie!

In fairness, I didn't know what I was going to get back so at least this made me smile.