Construction Report: Building Blocks

I promised you all some further comment on Faswall, the masonry system we’re using to build the earth-sheltered walls of the house. A person might wonder how big a deal it can be, the kind of masonry you use to build a wall that’s going to be hidden in the hillside when it’s done. It’s a great big deal. No end of reconsideration and negotiation has gone into the choices for these walls: we weighed cost, structural attributes, cost, delivery mechanisms, cost, insulative qualities, cost, availability, cost, and… cost.

So, here they are, freshly delivered, a house in a bag, more or less,

like a giant kit of Legos.

Getting them delivered was no small thing. One morning I stepped around the corner of the barn to see a semi with a 48-foot trailer easing itself over the hill. The driver, who must have been 80 years old if he was a day, got out and sauntered over to the excavation site. He peered down the driveway, hung his thumbs in his suspenders, and said, “That trailer ain’t goin’ in there.” And that was about the end of the discussion. Having it explained that if he drove around the hill and came down to us from above, sliding into the driveway would be easy, made no difference. He was arrived as far as he was driving. The fact that a crane was standing by ready to pick the pallets off the trailer and swing them into the excavation, if the load could get close enough, didn’t help. The fact he had driven 100 miles to deliver wasn’t persuasive. He pointed out he was on “detention time” and the more he waited for someone to figure it out, the more was the detention bill. Somebody just better work out how to get the blocks off the trailer. In the end, he conceded to drive down the road (refusing still to back down, which meant he had to back out later on, onto the road where cars come around the bend at 50 miles and hour). The crane moved the pallet loads off the trailer and stacked them on the roadway. And there they rested, waiting for the hands of strong men to move them, old-style in wheel barrows and on hand trucks, onto ramps for sliding down into the pit.

They look like cement blocks, so what’s Green about them?

Faswall blocks are 85% wood chips (the remainder is Portland cement and fly ash). Here’s a close look at one:

The wood chips, or any other cellulose fibers, are bonded to the cement in a process they call “mineralization,” which means the sugars in the cellulose are no longer available to rot-causing organisms.

Standing among the blocks stacked in the site and looming above his head, one of the masons looked up and said, “I’m wondering where the cheese is.” It was a maze of blocks, and a man could disappear among them.

They are indeed like a bunch of great Lego blocks, with keyholes to fit them together, and channels for the rebar.

The blocks carry a 4-hour fire rating, are sound resistant and pest resistant, are suitable for seismic areas, and can be cut with carpenter’s tools. Here’s one that’s had a hole cut through one side using a carbide holesaw.

They breathe and are hydroscopic (air and moisture move in and out of the blocks), do not outgas fumes, and insulate with R values of 18-23. They require half the concrete fill of conventional blocks, and are made with locally available recycled or waste wood.

And, it’s manufactured in Philomath, Oregon, less than 100 miles from us.

It sounds like the perfect building material, and a person now wonders why, if as the ShelterWorks (Faswall) website says, “After World War II amidst the rubble and destruction a way was discovered to take the huge volumes of wood waste, grind it into chips, mineralize the chips to neutralize the natural sugars that cause rot, and bond them to cement to form a building block,” … WHY AREN’T WE USING IT MORE? My goodness, that’s been, what? 60 years!

So, here is a view of the progress on our post-war house.

That girder you can see running around the perimeter of the walls just below the top is the level of the second floor. It’s comin’ along!

Published in: on October 19, 2008 at 7:40 pm  Comments (1)  

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One CommentLeave a comment

  1. Found your website via Twitter feed, loving the articles, thankyou.

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