Tar on block walls?

[central1ny]

I am considering a block foundation for my attached garage & covered breezeway. Is there any reason to consider having tar applies to the block walls since this is not living space?

 

[Professur]

It's a waterproofing.

 

[central1ny]

Thank you and I understand that it is waterproofing. I guess I am asking will there be any damage to the block walls over time if the tar is not applied? Does it matter if it gets applied? Is it standard practice?

 

[kbs2244]

Assuming you are going to back fill the inside there is no need.
The moisture level of the dirt inside and outside will equalize.

 

[Torque1st]

Tar may help prevent water from entering the block cavities and freezing.

 

[i4ni]

The block itself will act like a sponge and will always be vulnerable to freezing . Sometimes certain soil types in direct contact with the mortar can have a degrading effect causing the mortar to soften some what . Most of the time tar alone is regarded as more of a damp proofing than a waterproofing basically because of its tendency to become hard over time and develop cracks. There are better products available but at a minimum I would use tar over nothing at all.

 

[central1ny]

Can you give some examples of waterproofing products, or what would be better to use than tar?

 

[i4ni]

Google foundation water proofing. Your masonry contractor can put on a parge coat which is similar to stucco in that it takes a scratch coat and then a top coat which when troweled smooth like concrete is highly resistant to water infiltration providing your foundation doesnt settle and crack.The spray on water proofing is popular because it is capable of stretching and can handle some minor shifting and is the fastest to apply.There are Stick on Sheet products that are very effective but everything has to be super clean and dry. One more is a plastic (platon) product that creates a barrier between the soil and the block and uses standoffs to hold the prodct off the wall slightly to allow air circulation to help keep the wall dry . There are asphalt type(tars) that are better than others and actually use a mesh to further stregthen the bond and span .good luck