Spacing of Contral Joints in a Basement Wall 1

[rahuldby]

Just wanted to have a second opinion on this. I did some research and found that contral joints in basement walls are provided for every 20 to 30 ft. Is this typical for any thickess of the wall or is there any other better way of determining the spacing based on thickess and other factors included. Thanks in advance.

 

[golf39]

Assume you mean reinforced concrete walls not CMU. Recommend you go to

http://www.nrmca.org

"National Ready Mix Contractor Association" and go to CIP 7 - Cracks in Concrete Basement Walls, which uses spacing of about 30 times the wall thickness, with some other recommendations. I have used this and have had no problems. Hope this confirms what you are using & helps.

 

[concretemasonry]

Control joints are very rare in typical residential basement construction.

This is particularly true with concrete block basements where the materials (CMUs) have lower shrinkage than poured concrete and the units are cured before installation. Poured walls will have more shrinkage since the concrete must cure, but the same environmental conditions after curing will prevail.

If you attempt to predict cracking, you must consider ALL the factors - curing shrinkage, moisture shrinkage and temperature shrinkage and any offsetting corresponding volume change effects.

The major reason for the lack of control joints is the uniform moisture and temperature conditions the walls are exposed to. The practical problems of moisture control outweigh the risk of uncontrolled cracking.

Dick

 

[rahuldby]

golf39 and concretemasonry -

Thank you for your valuble input.