Tuesday, November 29, 2011

Temp rainwater collector, hallway "shadowbox", and Building Code clarifications

The night before last, we had another rain event that dumped a signifiacant amount of water in our area (over 1" in some areas).  We ran a small experiment using some scrap roofing metal to funnel water from one of the valleys in the roof into one of our 275 gallon collection tanks.  Monday when I left the site there was very little water in the tank but when I arrived Tuesday morning there was over 125 gallons in the tank.  The amazing part of this experiment was this was a very small section of the roof - only those areas of the standing seam that actually hit the one valley provided the water which effectively was square of about 10' on a side.  If you extrapolate that to the entire roof we would probably have collected over 1000 gallons from the whole roof.
Our experiment - that's just a section of roofing that happened to fit lengthwise and had about the right shape for a makeshift gutter.  The upright "stop" is another section that fit inside the IBC opening (9" opening).  You can see the hose bib (spigot) connected to the 2" ballcock valve on the front.  That was the hardest part to figure out since it doesn't appear to be a standard NPS thread.  I simply bought a 2"to 2" rubber connector, a 2" to 3/4" PVC adapter and a threaded spigot.  The rubber connector is held by standard clamps.  Over two nights this rig collected nearly 150 gallons of water...

Here's the marking on the Schutz IBC container - you can see it's slightly less than 150 gallons in the tank.

This is the 2" connector on the ballcock.  This is the water tank we're collecting the dehumidifier output from as we rid the house of the humidity from the mudding and taping as well as the concrete used for the pre-sloping of the shower drains.

  We're only planning on collecting from the rear half of the roof at this point in time due to logistics of piping the water from the front to the back of the house.  Depending on trenches and cost we may decide to run a separate pipe in the same trench to our collection tanks that will reside under the back deck.  Overflow will then be channelled into the runoff system going to the rip-rap outlet and feeding the 'water feature' in our landscape scheme.  Basically we'll turn a pile of rip-rap into a dry creekbed that will funnel water into the intermittent creek when it rains like it has here recently.

The "intermittent" creek after a good rain - it's been running, albeit a little slower than this, for several weeks now.  
The tile installation crew started installing the Durock Fiberrock for the shower walls Monday and as they were working, we started wondering about when the pre-slope would be installed under the pan liners since the liners were previously installed by the plumbers.  It turns out that North Carolina has opted not to include the IRC requirement for pre-sloping in the State code.  What that means is each county sets the rules for the pre-sloping and because of the difficulty in enforcing (as well as the strong plumbers trade push NOT to require pre-slope) most counties apparently Opt-Out of this requirement.  Fortunately our installer knew how to do this and while it wasn't included in the original bid, we had them remove the pan liners, pre-slope the pan, and reinstall the liner.  Unfortunately we were not fast enough to notice this before the FiberRock backer board was installed so the tilers had to pull down the bottom row in order to get to the liner.
A properly pre-sloped pan.  The slope is set at 1/4" in 12" so it's not a severe downslope yet water runs toward the drain.  

One other discovery we made was that there is no code requirement for waterproofing behind the tile.  Our plumbers use the USG Fiberock backerboard which is a gypsum based board (paperless) for wet locations. The manufacturer's rep was clear that it is not a waterproof material and while their installation guidelines don't include any mandate for waterproof membrane, the highly recommend it.  After further discussion with the USG Rep and a group of experts on the John Bridge Discussion Group, the consensus was that a waterproofing membrane was necessary to prevent future failure (an estimate of 5-8 years down the road).  Some recommended a 4 mil plastic behind the backer board and others recommended a liquid applied on the tile side that bonds with the board for a continuous membrane.  The concern over trapped moisture behind the plastic drove us to look at the liquid membrane.  One significant caution was clear - you can't do both or you'll trap the water between the plastic and the tile - or right in the backer board.  Our installer already uses the Mapei Aquadefense tape and liquid membrane for the critical areas (corners, drain, curb, ...) so we chose to get the material and apply the membrane over the whole backerboard up to 6'.  The instructions call for two layers applied at the critical points and then two more layers applied over all areas of the backer board.
The Fiberock is installed over the PVC shower pan membrane. This has not yet been taped and waterproofed.   

  Our take-away from this experience is to verify what parts of the code books are applied in your county/state.  The IRC isn't mandated as an all or nothing and in this case "County Option" is the rule of the day.  Unfortunately we learned this a bit late in the process so it's costing a bit of time and money to make it meet the IRC requirements which in this case we feel are warranted.

Today we finished installing our painted sheetrock in the spaces over the slatted ceiling areas in the hallway.  THe next step will be to get the hickory which will be 1x4 nominal (3/4" by 3 1/2") spaced 1/2" apart with the can light centered in each.
The black sheetrock installed with the temp light installation below them.  Hickory slats will run lengthwise (Top to bottom in this picture) in each bay with the can lights over the slats and below the sheetrock. 

Again the black sheetrock - looking toward the family room and kitchen.

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