Saturday, May 30, 2015

Odds 'N Ends - Managing Salvaged Lumber

This is the first of two posts on working with salvage lumber.

Work Table
De-nailing boards can be boring and tedious if the work area is not efficient, particularly when the volume of de-nailing is great.  Most of my salvaged lumber came from tearing down three old houses, two garages and several farm outbuildings.  The amount of de-nailing was substantial and seemed daunting at first but, once I got set up with an efficient work area, turned the radio on to PBS and settled into a routine, I rather enjoyed it.

The shanty for the work bench, provided mid-day shade and support for the work table.  The latter had several two-by-
Shanty-covered work area constructed from salvage
four arms extending outward from under the table as well as several blocks on top of the table (click on photo for closer look at the work table arrangement).  It also had a trough at the back of the work surface into which the nails could be tossed.  Because the boards usually had nails protruding from more than one side or edge, the table top was seldom useful.  However, the naily boards could be suspended between the 2x arms or between the blocks on top of the table and de-nailed without the boards wobbling around.  The working height of the table was lower than might be expected in order to gain plenty of leverage with less effort.

Four tools were most effective for pulling nails -- a claw hammer,  a flat tool, a wrecking bar
and an end cutter long enough to have leverage but no so long as to be unwieldy with one hand.  A short piece of 2 x 4 for a pivot under the claw hammer or end cutter, and sometimes the wrecking bar, was necessary for pulling long nails.  A circular saw was also mandatory.

De-nail or Cut-off?
During deconstruction, when a wall could be laid down for dismantlng, the top and bottom plates could be driven off of the studs with a sledge hammer without damaging the ends of the studs.  However, when walls were dismantled while still standing, the more usual case, the
A naily stud suspended on 2 x 4 arms; notice the toenailing
studs had to be driven sideways off of the plates which invariably damaged the ends of the studs.  Rather than wasting time removing the nails from the damaged ends, it made sense simply to cut off the studs, nails and all, with a circular saw.  Such was necessary more often than not when the stud was toenailed with four nails even when the wall was laid down for dismantling. Unfortunately, the shorter boards are not suitable for reuse in a typical 8' wall without being spliced.

The lumber brought in from the tear-downs was piled randomly in the open for several months without deterioration even in our hot, humid summers.  The randomness and the protruding nails provided plenty of air space between boards to keep them air-dried. After de-nailing however, the need for proper stacking became critical, which is covered in the next post on salvaged lumber.

Sunday, May 10, 2015

Construction - French Drains - Design, Fabrication and Installation (Cont'd some more)

Grading of the Building Site and Setting the Laser
My excavation of the building site left uneven contours in which water pooled after a rain. The first thing that the contractor did with a track loader just before a frog-strangler rain was to smooth and slope the grade.  As a result, the site was dry enough in a couple of days to resume work.  

The laser beam was then set up at 5' above final floor height to serve as the bench mark for all subsequent excavation and grading.  The proper fall for French drains is the same as for soil pipe -- quarter inch per foot which is a 2% fall.  The laser was then set for 2% to avoid having to calculate the fall as the trenching progressed.  For instance, the easternmost trench began at the north end at 14'  (5' from laser to floor level plus 9' below floor level)  and ended at the south end near the future rain garden at 17' automatically.

Rock for Backfill
Several truckloads of two kinds of rock for backfill were delivered by the contractor -- natural pea gravel (the brown pile in photo) and 1" clean quarry gravel (the light gray piles). Since the French Drains were made from
In goes 1" clean
single wall culverts (French drain construction) and might be damaged by backfilling with 1' clean from a height of over 10', we decided to bed the drains on a few inches of pea gravel then cover them for a few inches with more pea gravel before dropping in the 1" clean.   In addition to protecting the culverts from the coarse rock, the gravel would also facilitate water flow into the perforated culverts as well as carry water parallel to, but outside, the culverts -- at least for a while. Our soil engineer had warned that any gravel not protected by the proper geo-textile fabric would eventually silt up and behave more like the adjacent soil. As far as the the 
geo-textile wrap for the culverts was concerned, it was designed to filter out silty soil whether it contains gravel or not, thereby rendering future siltation of the gravel moot.

Last-Minute Changes to the French Drain System
The drawing shows the planned French drain system having seven north-south
N-S French drains in green and yellow; manifold in red (click on photo to enlarge)
drains with some of the eastern-most connecting with a diagonal "manifold" that empties at a future rain garden. While the internal diameter of the seven drains is 8", the connecting manifold is 12" and of double-wall construction in order to bear the weight of heavy vehicles on the driveway. 

What the drawing does not show are two last-minute changes to the system.  One is a long east-west French drain connecting the north ends of the seven north-south drains. The culvert-less trench was lined to a height of 6' with geo-textile fabric before backfilling with rocks and closing at the top with a "burrito wrap" of the fabric.  

The original design for all seven of the N-S drains was a pea-gravel-protected, fabric-wrapped, perforated, culvert backfilled with 1" clean and topped off with soil.  The trench was not to be lined with fabric. The second last-minute change was to use the same fabric, rock backfill and burrito wrap that was used for the E-W connector for the eastern-most (#7) drain even though it already had a wrapped
Digging E-W connector to a depth of 9 feet
culvert at the bottom. The rationale for these changes was to intercept ground water as it flowed from N-E to S-W anytime the water table rose decidedly above the height of the wrapped culverts (9' below floor level) even though the probability was minimal. 

Trenching, Installing and Backfilling
The trenching was done by a backhoe with a 24" bucket beginning with the N-S connector then the westernmost N-S drain and progressing eastward with the rest of the drains.  As soon as a trench was dug and the bottom lined with a couple of inches of pea gravel, the pre-made wrapped culvert was snaked in and lowered into place with ropes by enough volunteers to ensure its safe handling and proper orientation in the trench.  As soon as the drain was in
"Snaking" in a pre-made French drain
place, it was embedded in more pea gravel then backfilled with 1" clean to within a couple of feet of the top.  Then enough soil was swung in from the 
next trench being dug to bring the backfill to grade.