Monthly Archives: April 2010

Starting on the new sewer lines

It feels like we are nearing the end of a long journey. Early this year, we started with the basement sewer project by finding the old sewer lines, inspecting them, and deciphering how they worked.

We took the old sewer stack down, began to think long and hard about a new sewer layout, and finally came up with a good solution. We trenched for the new sewer lines, removed the old vitrified clay pipe, and cleaned out the grease trap.

And finally, (imaging the drum beat) everything is place to install the new cast iron soil pipe (CISP) sanitary and storm sewer. Boy, have we been waiting for this day!

It started early in the morning with the delivery of the CISP and accessories. I looked at the pile of cast iron laying in the back yard and knew that I had we had the work cut out for us over the next couple of days. Don’t think that I am mad enough to attempt the installation myself. I had professional help from Mariusz, Peter and Chris.


As with the trenching, we started the installation in the front of the basement. We removed the old check valve, which I had left in place ‘til now and connected with a non-shear coupling to the existing six inch sewer, which was coming into the building from the street.

I never would have thought that hauling around cast iron piping could be so much fun.


Raking, and no end in sight

No, not in the yard but in the basement – on the foundation walls.

Because the landscape around the house does not drain away from the building everywhere, the foundation wall had wet spots. The previous owner “solved” the problem by covering the limestone rubble foundation with cement parging, effectively trapping the moisture in the wall.

Trapping moisture in a masonry wall is always a very bad idea. Our plan is to solve the drainage problem around the house, insulate and waterproof the foundation wall from the outside, but let it breathe and dry out to the inside.

Great, except we first have to remove the parging, which was for most part a pretty painful job.

parging-removal-01 parging-removal-02

I am eternally grateful to Cathy and many of our friends who chipped away for days, until all parging was gone.

Are you hoping it goes uphill from here? Not yet, because next I have to rake out the old foundation joints so that I can repoint them. This is almost as painful as the parging job (forgive the upbeat description).

I began with the grinder, removing any cement residue and sections of hard mortar. After that I raked out all loose mortar to a depth of two to three inches at times. Last but not least I will need to wash out the joints before I’ll be ready for repointing.

I did not realize how long our foundation wall is, until I started this job! The really scary thing is that I may have to do the same job again on the outside of the foundation wall.


Grease trap cleaning

We have this big, old, ugly masonry grease trap in the basement portion of the back porch. Over the past century it received all of the waste water from the kitchens. It also received roof runoff from the downspout. Both roof runoff and kitchen waste water exited the grease trap through the main sewer.


When we took a first look at the grease trap early last year, we found a big old stinking, gooey, gunky mess with big and small chunks of grease floating everywhere. Now a year later, it still is stinky, greasy, gooey and gunky. But now it’s time to do something about it – it’s time to clean the mess. Yum!

I got myself a small paint bucket, perforated it with small slots, screwed it onto a long stick and started scooping the all that deliciousness out of the basin. Once I had most of the goo removed, I dropped a small sump pump into the pit. That worked only for a short while, because the small floating gunk clogged the sump pump screen.

Fair enough. I went to the equipment rental place around the corner and got myself a small trash pump, which got the job done, and the basin was finally empty in no time. I now could remove the old incoming sewer lines and part of the rotten brick work.


We eventually will remove the grease trap and a sump pit for the footing drains that will take its place. But that has to wait until we get to the porch rebuild. For now, I need to have the storm sewer line temporarily terminate in the basin so that it can pick up the roof runoff.

We also will temporarily terminate the footing drains in the old basin, until we install the new sump pit.


Trenching for new sewer lines

With the spread footings excavated, we now can finalize how exactly to route the sewer lines through the basement. But first we need to remove the old vitrified clay tile sewer, which we traced and exposed a while ago.

We start with the excavation for the new sewer at the connection to the existing sewer, i.e. where the existing sewer comes into the building. The elevation of the existing sewer is something we cannot change, and is thus the logical starting point.

While trenching through the basement, we make sure that the bottom of the trench steadily rises at a slope of about 2% (or about a ¼ inch over 1 foot). The slope is needed for proper waste water flow out of the building. Paying attention to and finishing the trench invert with the correct slope will make the upcoming sewer installation a whole lot easier.

Trenching for the main lines (storm and sanitary) is straightforward. Figuring out the trenching for the check valve and all basement plumbing is like shooting from the hip. It is difficult to finalize until we have all the tees, wyes, bends, and vents actually laid out.

I gave it my best bet and hoped most of it would fit the plumbing, although we may need to excavate some more during the sewer installation.


Spread footings

I am still stuck in the basement, and will be for a while. We have figured out the new sewer layout and know the scope of structural work needed for the green roof. Now it’s time to bring the shovel out of retirement.

We start with the excavation for the spread footings, which will accommodate steel pipe columns to manage the extra load of the planned green roof.

The spread footings take up some space, each four by four feet to be exact. We have to snake the sewer lines in between the existing and new footings from one side of the basement to the other.

By excavating the four by four patches first, we can determine the exact run for the new sewer lines and make sure they won’t end up under the footing.


The green roof dream

A vegetable garden on our roof has been on our wish list for a while. The question is if we can pull it off.

There are structural and budgetary challenges and they are closely linked. We have some very impressive steel columns supporting an equally impressive steel beam running near the center of the basement.


This assembly supports the interior load bearing wall of the 1st and 2nd floor and appears so sturdy that I was convinced it would support a green roof.

The actual roof structure, the 2 by 10 old growth joists running across the building, did not generate much confidence. I assumed this was the weakest structural link and would not support the extra weight of the airy vegetable plots.


How much structural reinforcement is needed? Are we talking about $500, $5,000 or $50,000? To find out, we need a feasibility study from a structural engineer.

I got Kerry from Louis Shell Structures (LSS) to take a look at the house and structures with me. He was very happy that I had all the walls open. He actually could look at and measure all load bearing components, which we did for about two hours.

To accommodate the vegetable garden, I assumed a growing medium depth of 6 inches and a drainage layer depth of 2 inches. All in all, a load capacity of 80 pounds per square foot (psf).


Kerry took all this information back to his office and began to crunch numbers–a lot of numbers! Lo and behold, the results were somewhat unexpected.

What I assumed to be the most solid component, the steel columns and beam, turned out to be a weak link. And what I thought to be the weakest link, i.e. the roof joists, appeared to be rather sturdy. Almost all roof joists are fit to support the additional 80 psf, with the exception of the long span area over the dining room and the kitchen.


Over the dining room area, I will need to sister the existing roof joist with two 2 by 10s (one on each side). Over the kitchen area, I only would need to add one 2 by 10 to each existing joist. All roof joists will need vertical blocking over the load bearing wall. And that is it for the roof structure!


As for the interior load bearing wall on the 1st and 2nd floor, we need to add some minor reinforcement. All typical door openings need a new 2 by 8 double header to transfer the load.


The larger opening for the French doors has to be reinforced with a double-LVL header (2 by 9 ¼ inches).


Some of the studs in the load bearing wall do not line up with the floor joists, which prevents proper load transfer. To solve this problem, we either need to add studs, or move the existing studs under the floor joists.


Last but not least, we have the unexpected weak link in the basement. It turns out that we will need to add a 4 inch steel pipe column half way between each existing steel column. The new columns will require a 4 by 4 foot concrete spread footing.


As for the budget, I think we are probably in the $5,000 range for these reinforcements. I am not sure when we will be able to put up the green roof. What I do know is that we should take care of the reinforcement now, while we have the chance.


Transportation folly

… or should I call it Truck folly?

February 2009: I have a long laundry list of preparations for the upcoming purchase of our house and the planned remodeling. On that list is the purchase of a pickup truck so that I can haul materials around.

Great idea, except that most times I am just driving the 1 mile from our current rental place to the house and back, hauling next to nothing.

Let’s see:

  • There is myself (around 215 lbs),
  • the dog (around 75 lbs),
  • a tool box (around 100 lbs),
  • a tool bucket (around 40 lbs),
  • the document and lunch bag (around 10 lbs) and
  • the camera bag (also around 10 lbs).


All together, we are talking about 450 lbs that get hauled around with a 5500 lbs truck. Even better, 290 lbs of the 450 lbs (i.e. myself and the dog) wouldn’t even need the truck. We could use our 6 legs and walk!

That leaves me with only 160 lbs of equipment that need hauling most days. Using the 5500 lbs truck for this job suddenly seems grotesque.

Solution: we talked to our bicycle friends at the HUB. Sam pulled a very sturdy bicycle trailer out of the basement, I mounted a hitch to the back of my bike, and the dog and I get our exercise twice a day, riding to the house and back.


This mode of transportation reduces my carbon footprint, saves money on gas – and it’s fun riding around and making heads turn!



Why that storm sewer?

Some of you who have read the ‘Permit – open plan review’ post, or who have noted the storm sewer in the ‘New sewer layout’ post, who know the 168 Elm pilot project and our attitude towards stormwater management may wonder why we spend money on a new storm sewer connection.

Disconnecting roof downspouts in Chicago is a tricky subject. The Chicago Green Homes Program encourages disconnecting downspouts from the sewer system. The Department of Water Management and Department of Environment are working hard on incentivizing disconnections. There is even a building code section that addresses this issue (Chapter 18-29-1101.2):

“1. Nothing in this provision shall prohibit the temporary or permanent disconnection of the roof downspout of a building from the sewer or combined sewer so long as the disconnection does not result in the drainage of water beyond the property lines of the lot on which the building is located.

2. Roofs of single-family (Class A-1) and multiple-family (Class A-2) buildings may be provided with external downspouts discharging onto a paved or landscaped area, provided the water thus discharged can be drained directly to an area drain, catch basin or street gutter connected to a public sewer, without spilling over onto adjacent property creating a public hazard or nuisance.”

That said, the plumbing inspector in the Department of Building won’t have any of it. When I raised the issue during the open plan review, I was told in no uncertain terms that disconnecting the downspouts is not an option. I would not receive project approval unless I showed a downspout to sewer connection on the plans.

I have to admit that I did not show up with engineering drawings and calculations that would have shown how I will manage the roof runoff on the property without flooding my neighbors. I think I would not have signed off either without a complete and sound design.

But when I asked for my options, like I did with the 1 inch water service, I was given none, despite the above stated code section, and despite existing precedence in Chicago.

So – do I want to fight over the disconnection, or would I rather keep a storm sewer connection?

I’d rather keep the connection to get the city’s approval and to keep going with the project. Once we are done, we may disconnect after all, if the sustainable stormwater treatment methods in the yard can handle all the runoff.

The primary rationale to deny downspout disconnections is to assure the public’s health, safety and welfare. How would a connection to the storm sewer help with that public health, safety and welfare, considering that the combined sewer system in Chicago is readily overwhelmed? Wouldn’t it just add to the flooding? Wouldn’t it be safer to siphon some of that water off and manage it outside the sewer system?

I have difficulties following the rationales and reasoning of the inspector.


New sewer layout

The big sewer question is resolved, thanks to our friend Jonathan. He commented on the post and sparked the ideas leading to the solution.

Rather than having all the basement fixtures draining through an ejector pit (Option 1) or installing a check valve (also called backwater valve) where the sewer exits the building (Option 2), we now have an Option 3:

All the basement fixtures will drain through a check valve before connecting to the main sewer line. This way all the basement plumbing is protected from flooding. Not only that, but it eliminates the need for pumping, because everything is now gravity fed.


We still could install an ejector pit with a pump upstream of the check valve. The assembly would only kick in during flooding, i.e. when the check valve for the basement plumbing is closed. Because there is no history of basement flooding in our house or on our block, in addition to the fact that I would like to get away from any pumping, we decided against it.

Furthermore, if there is flooding, the check valve would typically close only for a matter of hours, thus limiting the time of disruption for all basement fixtures.


The water service problem

I got freaked out pretty badly in the open plan review meeting over the code-required water service upgrade from 1 inch to 1 ½ inch, mainly because of the additional $10k to $15k price tag.

Once I got over the initial shock, I asked the plumbing reviewer what options I would have if I didn’t want to upgrade. Asking doesn’t hurt, right? To my surprise, I was presented with the following option (I paraphrase):

“If you can get a code variance letter from the commissioner of the Department of Water Management (DWM) saying that they are OK with the existing 1 inch water service, then we will be OK with it.”

I felt much better already, even though I had no clue to what my chances were to actually get that code variance.

The next logical step was to get on the phone with the plumbing inspectors at the DWM to present my case. I explained that we have applied for a green permit, that we are rehabilitating a three unit building and that we have plans for exceptional water management with all the low flow fixtures.

I was delighted to notice that the inspector was actually willing to evaluate if the 1 inch service line would suffice for the project. He asked for the plans and product information on all fixtures, which I e-mailed him right away.

Based on this information, the plumbing inspector added up all fixtures and developed a worst-case scenario. It is basically a calculation of how many gallons per minute (gpm) are needed at peak use and whether the existing 1 inch water service can deliver that amount.

More good news! It appears that the existing 1 inch service must do the job, because I was asked to submit a formal letter in which I applied for the variance. My case was presented to the commissioner and I received the variance approval shortly thereafter.

I took the letter back into another open plan review meeting, in which I received the missing final sign-off for the plumbing. All plans and documents went back to our green permit project manager who issued the permit a couple of days later. It was time to celebrate – and we did!

The water service issue added another two week delay to the green permit process and made me jump through a few more hoops (thank God I am somewhat fit!). It also saved us $10k to $15k, which we had not included in the budget. Plus, the green permit means we had no permit fees. Not such a bad deal after all!