Old Brick Walls Stresses 1

[youssef91]

I'm trying to find any material stresses information for brick walls for a house built in 1920.
The owner wants to change an existing flat roof to an open roof deck,plan checker asked for a complete design for the brick wall supporting this existing deck as the life load has been changed.
Also, is there any information for drill and epoxy for this type of old brick walls?
Any help is appreciated

 

[youssef91]

A correction made for live load in lieu of life load at third line.

 

[JAE]

Looking up material stresses for brick that old may not be accurate for your particular condition as the material properties may have changed over time - with exposure to moisture and thermal swings.

I would think that if you refer to ACI/ASCE 530 (which includes clay brick) and its associated ASTM references, you can first get a feel for the full range of stresses allowed in brick. Keep in mind that older brick used softer mortar (higher lime content) and so while the brick may be strong, the masonry (brick + mortar) may be much less.

If you can take a prism sample from a non-visible area of the wall, any local testing lab can get you a prism test performed that would also give you an ultimate stress capacity that you can then relate to a design f'm.

 

[pba]

Based on experience - Before testing, do some calculations assuming very weak masonry to see if you are in the right 'ballpark'.

I am not familiar with bricks in the US, but UK bricks would not be expected to deteriorate within 80 years. When we have similar situations here, we have found that it is worth speaking to the local merchants as to the possible brick type as regional variations can be signifficant.