Tag Archives: recycling

Cracking concrete until the foundation falls

Our old back porch was special in many ways — just not in a positive way. For instance, it had two foundations. One was an old limestone foundation wall (more on that later), and the other was a reinforced concrete foundation in front of it.


The concrete foundation was added sometime in the past 10 to 15 years to stabilize the limestone foundation behind it, which had started to buckle inwards. And this demonstrates the power of water and the importance of properly working drainage.


The buckle in the limestone foundation had its apex where the downspout met the sewer pipe. At one point that sewer pipe must have been cracked or broken, and probably blocked, behind the limestone foundation. Water rushing down the downspout didn’t drain but rather started saturating the soil behind the limestone foundation. The frequent hydrostatic pressure started to push the foundation inwards.

I could tell that the broken sewer tile had been replaced and the concrete wall poured to tame the buckle.

Our job for the day was to remove the concrete foundation.

There wasn’t much to salvage or recycle from the old porch. The concrete, however, is a sought after commodity. There are recycling stations that take it and process it into recycled aggregate.

Similar to the basement floor, I may end up getting part of my own concrete back when I install the recycled aggregate base for the new concrete floor under the new porch.

Related posts:
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Terminating the temporary

I mentioned the old grease trap in the back porch. It was a hot mess back in 2010 when I cleaned it up. The intent at the time was to temporarily re-purpose it as a sump pit.




Back then, I connected the interior perimeter drains to it. We also terminated and stubbed the new sewer lines, which allowed me to install and connect a sump pump.

This temporary band-aid has lasted long enough. With the old back porch being torn down sometime soon, I had a sense of urgency to demo the old grease trap. Before I could do that, I had to install a new and proper sump pit. And before I got to that, I had to rip out the old concrete floor.

That put me back into recycling mode. We threw the concrete chunks into the back of my truck and hauled them to the recycling company down the street at Kedzie and I55.

Next step: Getting the excavator and starting to dig.

Related posts:

The back porch project

Grease trap cleaning

Nail biter

Perimeter drain installation

Finished sewer

Where did all the concrete go


Hardwood floor restoration preps

Let’s complete the transition from the bathroom topic to hardwood floors.

We have the original 100+ year old hardwood floors through most of the building. They are largely in surprisingly good shape, because they have been protected for decades by layers of tile and carpet.

Although, if you did take a look at them after we had removed the various layers, it would have taken some imagination to see the asset they were to us.



We found a number of clues that indicated their suitability for reuse. And reuse at this scale (about 1,200 square feet of flooring) can make a significant difference. Not only in economic terms (just imagine the cost of installing new hardwood floors versus restoring and refinishing), but also in terms of resource efficiency.

What do I mean by that? Three options are often thrown around: 1) recycling, 2) salvaging and 3) reuse. Out of these three, recycling (or better downcycling) is the least desirable option as it is the one closest to the landfill. Reuse, on the other hand, is highly desirable because it conserves the value and embedded energy of a product or material.

The more of the building we can reuse, the fewer the resources we need to pour into the building, the smaller the overall carbon footprint, the greener the overall project.

Such an easy way to earn some bragging rights!

Now that we are so close to restoring and refinishing the floors, I tried to determine what preparations were needed. We cleaned most of the floors from the mastic and glue that was used as a tile adhesive. The oak floor in the living room had been painted dark red at one point. We decided that we needed to remove the paint prior to any sanding.

As usual, when it comes to removing paint from wood, Cathy’s Silent Paint Remover became very handy again.

After about 12 hours of work (stretched over three days) the paint was gone, and with it an endless number of small staples that were used to attach the carpet backing.


DWV Part 2 – details

We need to structure our DWV system in a way that allows us to separate the blackwater from recyclable greywater. That requires scrutiny of all waste water sources in the building and to assign them to the one or the other category.

Discharge from the toilet contains human waste and as such is blackwater. This is easy.

But what about the kitchen sink and dishwasher? Waste water from these sources is typically considered greywater. We are, however, concerned about the contamination potential through food scraps.

To keep things simple and to have peace of mind, we made the decision to discharge waste water from the kitchen sources with the blackwater and not recycle it.

Drain water from the shower and bathtub, on the other hand, is a perfect source of recyclable greywater. So is the water from the bathroom sink, except that there will be very little of it considering our low flow faucets at 0.5 gpm.

Last but not least, there is the washing machine in the basement, the waste water from which is also a good greywater source.

Let’s see how the categorizing of these sources fits with or impacts the DWV layout.

Structuring the sewer

The entire basement DVW plumbing was dictated by flood prevention concerns. We solved the problem by separating the basement DWV from the other floors and protected it with a check valve.

This solution has one drawback. The layout prevents us from collecting or recycling greywater from the basement fixtures. (The exception is the washing machine.)

The basement DVW system as well as the upstairs bathroom layout determined the location of the main sewer stack (or blackwater stack) that will serve the 1st and 2nd floors. It will carry the waste water from the toilets, kitchen sinks and dishwashers.

The 1st and 2nd floor bathroom showers and floor drains are connected to a secondary stack, which is a dedicated greywater stack. Right now this secondary or greywater stack is connected to the basement DWV system to comply with the Chicago plumbing code.

However, once the collection and recycling of greywater becomes permissible, we will be ready for it. We can insert a small collection tank with a little sump pump at the bottom of the stack. The small collection tank would still have an emergency connection to the basement DWV plumbing (as is the case now) in case of a power outage of failure of the sump pump.

The sump would pump the geywater from the small collection tank to a gravity filter from where it would flow into the final storage tank.

That takes care of everything, except the waste water from the bathroom faucet, which is some distance from the greywater stack, but right next to the blackwater stack. We probably could figure out how to connect it to the greywater stack. But is it worth considering the faucet flow rate of 0.5 gpm and the miniscule amount of waste water produced?

We always could go with an off-the-shelf greywater system, which is installed under the sink and routes the filtered waste water into the adjacent toilet tank for flushing. That is, once these systems are permitted by the Chicago Plumbing Code.

The waste heat layer

This exercise got us to think about solutions for greywater recycling. But there is another waste product that we didn’t want to ignore:  the waste heat in the greywater.

To recapture the waste heat we installed a drain water heat recovery (DWHR) system.

Going a few posts back you can read up on how we scrutinized the sources of waste heat, weather it comes from a greywater or blackwater source, and determined how it would impact the DWV layout.

We ended up placing the DWHR unit at the bottom of the greywater stack, just above the future collection tank.


DWV Part 1 – rationales

Let’s go back in time for the next posts. I would like to dissect the plumbing system some more. A good starting point is the drain-waste-vent (DWV) plumbing.

I described the PVC to CISP connection and the DWV basement installation. But I said little about the rationales and layout other than the discussion about the new CISP sewers and the check valve location.

The moment we look at what goes down the DWV plumbing, sustainability creeps into the picture. As the name suggests (drain-waste-vent) we are talking about draining waste water. Although, not all waste water is equal.


… is the term coined for the waste water we flush down the toilets – water that contains fecal matter and urine. Blackwater requires processing, typically in a waste water treatment plant, where pathogens and organic matter are removed. Only then and once disinfected is it safe (from a human health and safety aspect) to release into the environment.

There are a number of other, ecologically sound, smaller and/or decentralized blackwater treatment options such as constructed wetlands and the ecological engine, which have been widely researched and published.


… is the watered down cousin of blackwater. By definition it cannot contain human waste.

Greywater typically originates from the sinks, showers, bathtubs and washing machines of our homes. Because it carries lower levels of contaminants, it has a lower health risk.

As such, greywater can be recycled and reused. Typical applications for recycled greywater are landscape irrigation and indoor reuse such as toilet flushing. Outdoor use, and more so indoor use, may require some level of filtration.

Policy potential

We know about, and often practice, recycling – extracting another use out of a resource rather than letting it go to waste (pun intended).

Greywater is a resource that has recycling potential, given the right plumbing layout. Rather than having one DWV system that drains everything, it can be structured to separate blackwater from the recyclable greywater.

There is one minor problem, though. Our plumbing code in the city of Chicago does not allow the reuse or recycling of greywater, point blank. The Uniform Plumbing Code prohibits the use of greywater indoors.

I don’t think it takes a visionary to figure out that, given increased pressure on our natural resources, the current policy must expire sometime in the future.

Anticipating the policy change, we would like to avoid opening up walls to get to and modify our DWV system. Instead we would like to proactively structure our stacks and sewers for easy adaptation of greywater collection once it is permissible.


The shower curtain…

… is still missing. You may have read about our salvaged shower wall in the last post, but we still needed a curtain for the front.

I began to poke around online. Lo and behold the search term “recycled shower curtain” actually produced results.

I stumbled across the Bardwil Evolution Shower Curtain. It is, according to the product description, made of 100 percent post-consumer recycled plastic bottles. The bottles are crushed and repurposed into polyester yarn that in turn is woven into the shower curtain.

IAQ (indoor air quality)

I also found an online review that pointed out that this curtain is not as resistant to the onset of mildew as other products and requires washing and bleaching every second week.

Well, that sold me! Why? Because it probably means that the material is not treated with chemicals to prevent mildew and mold – although I don’t know that for sure.

But there is more to it. Mold and mildew on a shower curtain is typically an indicator for poor ventilation in a bathroom. What better way to put our ventilation system to the test!

We have been taking daily showers for the past two months, and there is not a spot on the shower curtain, or a sign of any discoloration which would be the first indicator that something will crop up.

Although we probably should put the curtain in the laundry sometime soon, I really want to keep it up for a little longer just to find out if mildew would eventually crop up.

But so far our ventilation system with the ERV appears to manage the moisture levels in the bathroom just fine.


3rd layer – rock wool insulation

I shared our experience with the 1st and 2nd layer of insulation in recent posts.

We originally intended to use spray foam for the entire wall section, but decided after some more research to add another material, or a third layer: a rock wool batt product.


What is rock wool? It was first discovered as a byproduct of volcanic activity, where lava came into contact with air and cooled into fibers. Modern manufacturing processes spin molten rock into thin fibers. The process is said to look like cotton candy production.

After adding a binder to the fibers and letting it cure, the batts get cut into the required dimensions and are ready for packaging.


The rock wool option subtly slipped into the picture for a number of reasons:

  • It has the thermal resistance we are looking for.
  • Unlike spray polyurethane foam (SPF), rock wool is not a petroleum based product.
  • It has a high recycled content.
  • Because rock wool is made out of stone and slag, it won’t burn.
  • It is a very economic insulation material (typically around $0.16 per board foot), more economic than SPF or recycled cotton batts.
  • Rock wool is very easy to handle and install.

I found two rock wool manufacturers (Roxul and Thermafiber) that distribute their products in Chicago. The Roxul Comfort Batt was sold for a price that fit our budget at the Chicago Green Depot, where I placed my order and picked up the material.


The batts are very light and dimensioned to fit between 16 inches on center wall framing or floor joists. Due to their somewhat soft nature, we could squeeze the batt, slide it between the framing and let go. Right away it expands back to its original size and firmly sits between the studs or floor joists.

We appreciated the ease with which rock wool can be cut. A long, serrated bread knife was the perfect tool to trim the batts to the required length or fit them around outlets and light switches.

The heat has been on for a few weeks and with all three insulation layers in the walls (an R-value of 25 to 27), we should be able to keep that heat where we need it.


Scavenging for framing materials

Our friend Drew and I are warmed up after preparing and installing the window bucks, followed by the doors. We considered starting with framing work in the basement, but first need to organize some 2 by 4s.

I am proud to say that the only lumber that I bought at a regular home improvement store or lumber yard to date was the treated material for the bucks and a couple of plywood pieces way back when. The remaining 95% of material has all been salvaged and reclaimed lumber.

Not only does it help with our resource efficiency goal, it also assists with our rehab budget. I have been fortunate enough to find salvaged and reclaimed framing lumber for the fraction of the cost of new lumber.

It gets even better, because of the material we got for free! We salvaged a good quantity of old growth and nominal framing lumber during the deconstruction of the basement and 1st and 2nd floor. We de-nailed it, cut of the bad areas and split ends and then organized it by length so it was ready to be reused for the new basement framing.


Although this will keep us going for a while, my count showed that the stack was not enough to finish the job. It was time to make another trip to the ReBuilding Exchange, where I found more framing material for the basement job.


Earlier this year, the ReBuilding Exchange was overflowing with construction lumber. This time around, the lumber section looked somewhat empty and I learned that a lot of the salvaged lumber was bought up by various community gardens for their raised beds. I am glad to see that the reuse market is growing!


I loaded up enough 2 by 4s to finish the basement job, brought them home and slipped them through a front window into the basement. Now we are almost ready to go.


Despite all my bragging about the salvaged materials, I still have to make one trip to the lumber yard. I decided I need to buy a handful of cedar studs for the bottom plates on the concrete floor.

We are going to great lengths to manage and control moisture in the basement. That said, if there are any moisture issues (such as a spill) they would first show at floor level. Thus our proactive interest in using moisture resistant material, i.e. the cedar studs at the concrete floor to bottom plate interface.


Installing the aggregate base

Now that I found a source for recycled ¾ inch stone and have my setup to bring it into the basement, I prepare a number of elevation points and started spreading the aggregate base.

One area, towards the front of the basement, is slightly over excavated. We used the old clay sewer to fill that extra depth, rather than aggregate.

I received enthusiastic help from one of our young neighbors when it came to break the pipes into small pieces. I learned that smashing old pipes is cool.

The recycled ¾ inch stone (also known as ASTM C33 #57, or IL DOT CA7) appears remarkably similar to the non-recycled crushed limestone aggregate. I don’t have a material test report to compare, but can tell that the recycled material is almost entirely composed of recycled concrete, with a couple pieces of asphalt, brick, metal and wood in-between.


The real significant difference is that I got the recycled ¾ inch stone for about half the price of limestone based aggregate.


Hauling recycled aggregate

It is 5:00 a.m. and the alarm clock is making noises. The only reason why I am able to tolerate getting up this early is that I get to play with a whole lot of recycled material.

I found a material supplier that accepts concrete debris from demolition projects, such as our old basement floor, and turns it into various aggregates. We need to put a minimum of four inches of aggregate base under our new basement floor. It can’t just be any aggregate; it has to be ¾ inch stone, also known as ASTM C33 #57, or IL DOT CA7. And I want it to be 100% recycled material.


Why am I so specific about the stone? Well, the ¾ inch stone lacks the fine particles and may have around 35% void space. With that size and void space, it acts as a capillary barrier, which prevents any soil moisture from migrating upwards to the concrete slab.

And then, of course, we have the soil gas issue. Any radon gas can readily collect in the void space and easily migrate toward the soil gas pipes, which will safely vent it out of the building.

Why do I need to get up at 5:00 a.m.? There is only one material supplier nearby that offers the 100% recycled ¾ inch aggregate. They open at 6:00 a.m. and close at 3:00 p.m. I need a whole lot of recycled aggregate and so I’d better get an early start.

I don’t have the smallest truck in the world, but felt pretty miniscule when it came to loading up. The whole truck could have fit into the bucket of the front loader that dumped the aggregate into the truck bed.


Back at the house, I parked the truck at the basement back door. We built a simple chute into which we shoveled the aggregate.


The chute dropped that aggregate into a wheelbarrow. My job for the day: driving the truck and wheelbarrow, all day long.