Roof and Exterior Wall Water Damage Assessment 3

[Adamian]

I am working with a local Home Owners Association of a 46 year old apartment complex on a damage assessment due to water penetrated through cracked stucco,
unprotected roof with shingles blown away by wind, flooding at stuffed rain gutters,... I traced water stains from mansard through the walls to basement.
My recommendation was to analyze and mathematically evaluate the main structure, identify damaged structural elements and design a detailed repair-retrofit solution.
My main concern was not only the health hazard due to mold but also the condition of the structure: rafters, joists, diaphragms, sheathing and nailing.

Structural engineer hired by the insurance company responded that most of the time these structural elements are being exposed to similar whether conditions during constructions,
and that unless I have evidence that the nailing at critical areas of horizontal and vertical diaphragms is displaced the structure has not changed.
I need second opinion, reference literature about this subject, and guidance on what steps to take to assure the building is safe.

This building is in Los Angeles.

 

[Ron]

I do a lot of these in an area that receives a lot more rainfall than your area. We see structural damage, sometimes major, in 3 to 5 years after construction, mostly due to improper weather/waterproofing details.

I routinely see compromises to the structural integrity of the structures due to water intrusion. Shear walls are compromised because of sheathing deterioration and/or fastener corrosion. Structural members are compromised due to deterioration from wood rot.

There are very few authoritative references on the subject. In fact, most of the stucco information out of your area erroneously states that stucco is waterproof! Hogwash!

Let me know what you need...I'll try to provide.

 

[dik]

It's a matter of getting samples analysed for 'dry-rot' conditions. Dry rot is a bit of a misnomer; it requires the conditions you indicate, ie. water. Significant damage can be done to the material at the point that it is noticeable. There is a bit of a discussion in the 'Encyclopedia of Wood' about the effects of this on the properties of the material. I'll include this when I get to the office.

Dik

 

[dik]

First upload attempt didn't fly... try again...

Dik

 

[dik]

Check our immunodiagnostic decay testing developed by the Forest Products Laboratory. I understand that they have a simple, inexpensive test that determines the presence of 'dry-rot'. I have a bunch of other papers on the matter of fungal attack of wood products.

Dik

 

[hokie66]

Don't forget the termites. They like moist conditions and all sorts of wood.