Filling A Gap Between Two Buildings 2

[kxa]

I was asked to look at a five story building for damage caused by excessive moisture at the ground level interior walls. During the inspection I noticed that when the adjacent five story building was constructed, they left a two inch gap where, despite the flashing at the roof parapet, allows for water, snow and humidity to get in there. Since there is very little chance for any air flow and the sun can not reach the area to help dry it, the wetness penetrates the building. Furthermore, there have been complaints about rodents.

I am suggesting that they fill the gap to the top with concrete. Perhaps with fly ash or a mix that is less permeable. I would like to hear if anybody out there has any experience with a situation like this or any other ideas. Thanks.

 

[Den32]

RacingAZ is on the right track - there needs to be some type of Expansion Cover over this 'gap'. Filling it with concrete is a very bad idea. This is an 'expansion joint' between the two buildings - putting concrete in there no longer allows differential movement and could cause new issues.

This (waterproofing, sealing, expansion covers,etc.) is a job for a competent Architect. If you are a Structural Engineer - I would steer clear of specifying the fix. You should identify the likely problem (as you were hired to do) and recommend obtaining the services of an Architect or Waterproofing Specialist for the Fix Detail. They should be able to figure out the best way to fix this waterproofing issue.

 

[kxa]

Thanks Ron, I will propose blowing out the cavity and then pouring 3’ to 4’ of concrete to maintain a good pitch and then spray the rest of the wall with tar like material. There is currently a flat flashing that is attached to our building wall and the other end rests freely on the other building’s parapet. I am also thinking of replacing this flashing with one that is pitched towards their roof so that snow and ice are removed more quickly. As a note, our parapet is higher than theirs.