leangreen.org recycled renovation on a low-budget ration

In an attempt to keep progress moving with materials we had on hand we took on finishing the walls in the downstairs bathroom. On a not too recent weekend (circa 2008) we found some cheap oak flooring leftovers on craigslist. With some ideas about what we could use them for we went and had a look. Much of the pieces were rejects due to knots or other aesthetic imperfections which didn't bother us much so we loaded it all up, drove it home and then shuttled it upstairs (blurry picture included to show the precarious wood stack). And there it sat becoming a makeshift, multi-level, wobbling sort of table/obstacle, a tablestacle - that sounds too anatomical, how about obstable. The obstable remained in place (albeit with frequent rebuilds from various collapses) until Jen came up with using it for the walls of the downstairs bathroom.

Once a firm decision was made we started planning and then attaching. In preparation we had to fir out some of the studs to get a level plane as well as add some nailers since many of these pieces are shorter than the 16" on-center span of the studs. Initially I tried using my pneumatic stapler to attach the pieces but found that shooting through the tongue I couldn't get a steep enough angle to keep the staple out of the way of the groove for the next piece. This led to the tedious process of pre-drilling the tongue and hand nailing using finish nails...slooooow. Fortunately while relaying this to my neighbor after the first day he let me borrow his propane powered pneumatic finish nailer that sped things up considerably.

Now we are trying to come up with a nice way to hide the hydronic tubes that run directly behind the toilet, but for now we are happy to have warm wood walls!

We installed PEX tubing in the drizzling rain and pressurized to 60 psi with success. We laid the tubing at 8" spacing except for the perimeter where we tightened the distance to around 4" to make up for heat loss at the exterior walls. We used zip-ties to attach the tubes to the 12" grid of rebar which is floating above 2" of polystyrene insulation and 4" of drainage rock. We have some concern about the lack of insulation at the perimeters walls, but the engineer and architect have specified that the concrete slab adheres directly to the concrete footings. We may lose some of the heating system efficiency, but we don't want to compromise the foundation's strength.

We had a minor delay in pressurizing the tubes for the inspection because our PEX-to-manifold adapters were for 5/8" tubing rather than 1/2" tubing. Our inspector showed up a little early, we weren't ready because of the adapter mix-up, and the inspector promised to return to verify the pressure and sign the job card before the concrete pour tomorrow.

For the concrete pour, we will forgo the tooling of expansion joints and accept the fact that cracks will occur in the slab which will be our finished floor in the entry, living room, kitchen and garage. We ordered a 7 sack mix (a high ratio of concrete) to increase the slab strength and finish quality. We also asked for microfibers in the mix to help prevent cracks. Over time, we expect a somewhat random or dendritic pattern of hairline cracks which might even be emboldened if we decide to stain the concrete. Our radiant heat expert friend, Jeff Stangeland, suggested that using iron sulfate for stain is a non-toxic alternative to acids and it would give the concrete a rust tone. That decision is a long way away. We hope tomorrow brings us a clean, strong and smooth-finished slab.

We have the PEX tubing for the in-slab radiant heat so we can lay the tubing before inspection tomorrow morning. We will layout two loops beneath this slab (shown in blue above), each less than 250 feet so that we get good hot water circulation through the slab. The concrete pour for the 36 foot by 13 foot rear addition is scheduled for Wednesday, right before it starts RAINING. We need to demonstrate that the tubing can withstand 100 psi of air pressure during the inspection, so we had to run out to find a manifold that would connect our loops to a pressure gauge and an air compressor. We'll post the inspection results!

Our attempt to obtain a mechanical permit for the radiant heating system failed this morning. The Senior Building Plans Engineer feared that our roof might collapse due to the added weight (a whopping 106 pounds plus a gallon of water at 18 pounds) of the solar hot water panels among other minor concerns. We will try again tomorrow when a more experienced plan checker is on duty. None of the city employees appeared certain if the approval should fall under a mechanical, plumbing or even electrical permit (for the solar hot water). Perhaps we should try for the cheapest one?

we need to lay PEX tubing for our radiant heat system before they pour the back slab. eventually, warm water will flow through the tubes to heat the concrete slab which is a 5-inch thick thermal mass. it should be clean, efficient heat but deciding on the right heat source took us extra time.

this heating system is a big investment and these decisions cause much head-scratching without the confidence of someone who has done it before. we found some help and we're working out the details this weekend and we'll post our plans.

if anyone has a few hundred feet of PEX tubing lying around, we want to install it this weekend.....not Monday! the crew would like to pour on Wednesday which means we need an inspection on Tuesday which means the PEX needs to be installed Monday. Our delivery should arrive that day. We'll be scurrying.