Split Bkock Problems, Phase 2

[Will Decker]

Well, it has started!

The old problems with split faced block buildings was water stains and mold growth. Now the 2nd phase has begun, structural collapse.

Did a single family house. Three stories with a penthouse and front and rear roof decks. The master bedroom was below the rear deck.

Thermal imaging revealed cold truss ends. Moisture meter pegged at these areas.

Cut open the ceiling (this was a consultation, not a pre-purchase inspection.

The roof trusses were TOTALLY rotted (you could put your finger through wood) and the trusses and roof decking were all black. Some very exotic molds.

See here for pictures: Split Faced Block builings problems update.| Decker Home Inspection Services. (http://deckerhomeservices.com/Split_faced_block_update.htm)

Look for some collapses, this winter.

Hope this helps;

[Michael Thomas]

Hey Will, nice to see you here at IN....

[Markus Keller]

No big surprise, had to start happening sooner or later. Goes along with the idea that some of us have discussed for a few years now that these CMU buildings will only have a 30-40 year life span.
The potential next housing bubble ... when people still have mortgages and the buildings are only demo worthy.

[Will Decker]

Here is a nice little experiment that you can do for yourself. I have been working on this for 2 years (but, of course, I have no life).

1) Buy a unit of split faced block.
2) Wet said block.
3) Place block in chest freezer. keep there for a couple of days.
4) Take block out and leave to thaw for a couple of days.
5) Re-wet block.
6) Continue, steps 2 - 4. Do this 392 times.

Today, when I went to pick up the block after step 4, it crumbled in my hand.

Looking at the block through a dissection microscope (hat tip to Nile North High School), I noticed that the "bubbles" in the block were radially fractured. Like brick fractures planar, but in a spherical 360 degree fashion.

So, does this mean that we will be seeing masonry walls just crumble?

This is getting interesting.

[john f miller]

Will,
These are truly professional and helpful posts. So much better than the name calling and sniping that some members feel are necessary. If I lived in one of these buildings I would be tempted to give it back to the bank and walk away!

[Garry Sorrells]

Will,
Interesting experiment.
How does your experiment convert into years in field application?

What is your areas number of freeze thaw cycles for the block construction?

[Dennis Thatcher]

Great post, and raises a good question, but like so much else in the built enviroment it depends on a host of factors, most of which relate to local long term weather conditions. I live and work in the high desert Rocky Mountain area and have seen first hand the destrictive force of several freeze thaw cycles per winter on even high density concrete, let alone soft "cinder block" walls. We have learned not to use brick or block as top caps for exterior walls, but to cap with metal flashing or precast and sealed cap stone, some native rock also works well. That said, we still rutinely use split face block for exterior walls, and seal it if it will be exposed to "wet" conditions.
Given enough time, anything we build will likely end up as a pile of debris on the ground, best we can do is look for materials that will survive for the "Design Life" of our building and hope for the best. Block, as a building material has some advantages and some disadvantages, it works well in some places and not so well in others. My recomendation would be to always engage the services of an experienced local Design Professional in the design process.
Dennis