Oil Tanks

Leave a comment

Q: We’ve found another property we are interested in.  It is bank owned so we are not able to get much background information.  We know that the property had an oil storage tank, and that they switched from oil to gas in 1960.  However, this was before Mercer Island was incorporated so the city has no record of the tank being removed or decommissioned.  Although, there is a record of a permit for switching from oil to gas.  Do you know how tanks that were no longer used were dealt with in 1960?  We were unable to find the filler cap when we were looking at the property so we don’t know if the tank has been removed or decommissioned.  Any insight you can offer would be appreciated.

 

A: Typically they were just abandoned. Usually with some oil left in them, it wasn’t worth the salvage a cost to remove it. It is common to find them this way on houses that were converted from oil to gas, prior to 1995.

Now we have them retired to code, requiring them to be pumped out, rinsed and then the filler cap broken off. The pump out typically includes any remaining oil and the water that may have found its way in.

So it maybe a good sign if the filler cap was possibly removed. It’s also good news if it wasn’t available for old oil and paint to find its way into it either.

You can try to locate it yourself or hire an oil tank company to come out and locate it with a strong metal detector and soil probes. When located, they can determine if has been properly retired and if not they will. If they don’t find it, we usually assume it’s been removed.

I always look for the obvious locations to install a tank, as the house was being built. There is an important rule of construction to always remember: if there is an easier way to do it, it usually was the primary option. Trenches and ditches are always the straightest possible line, to avoid extra digging; oil tanks are close to the foundation, requiring less excavation and shorter oil lines.

So look in the areas that required backfill first.

On the inside, or in this case in the crawlspace, look under the house for the oil lines. These small copper tubing, always a pair, will run from the furnace location to the exterior foundation wall closest to the exterior tank. Easy to trace when doing the dirty deed of exploring the crawlspace.

With a basement, it is typically in the area of back fill, closest to the furnace and chimney. Oil and older gas furnaces, as well as gas water heaters, were always vented through chimney or metal gas exhaust pipe, through the roof.

In a basement of a 1950’s and older home, look on the floor by the furnace for copper tubing breaching the concrete slab. The direction to the exterior location is usually discernable, often times with patched path of concrete, where they buried the tubing. It is common to find the oil / air separator mounted on the basement wall, it looks like a smaller copper tube running into a larger copper pipe and then back to tubing.

On the exterior, look for the filler cap in the yard, next to the house as well as the tank vent pipe. The filler cap is usually at grade, but sometimes just below. It will be within 5 feet of the house and within reach of the oil trucks long hose.

The vent pipe is typically a 3/4″ galvanized steel pipe, leaving the ground, next to the foundation. It usually runs up the siding about 5 feet with a ∩ (inverted U) shaped fitting on the top. The tank filler cap is at one end of the tank and the vent pipe exits the other. This vent pipe allows the air pressure to equalize in the tank and runs from the tank to the foundation wall and up the siding. If this vent pipe has been removed, you can look for built-up paint, on the siding, in its shape.

If you don’t find it, we can try to spot it prior to calling a service.

It is very common to find a tank not retired to the newer code, if it hasn’t been on the market in the last 15 years or the oil furnace was removed over 15 years ago. If it has been sold within the last 15 years, or the gas conversion was done since then, odds are good that it has been properly retired. So check the age of the furnace too.

It will cost about $350 to $400 to have it properly retired in place including all of the required documentation and $100 to $150 to have it located.

Removal typically makes sense if you expect to build an addition in that area, otherwise people usually let sleeping dogs lie and do the proper retirement.

Advertisements

Air Sealing

Leave a comment

Q: We are ready to increase the insulation in our older home, but we have been told that we need to air seal first. What do they mean and what is involved?

A: Before we add insulation to our attics or floors, we need to air seal our homes. Most homes can loose 20% to 50% of their heat through air movement passing through openings and holes in the envelope of our heated living space.

New homes, and ones built by conscientious builders in the last few years, address most of these issues. However, since most of our housing stock is over five years old, there are many areas that can be addressed and improved. Typically, the older the home the higher the return and the faster it pays for itself.

Common openings that need to be sealed:

  • oversized holes at the plumbing pipes and electrical fixtures.
  • the heat register transition to the floor
  • ducting with gaps open to the crawlspace
  • usually electrical outlets, wall switches, and ceiling fixtures (with attics above) are poorly sealed
  • poorly fitting fireplace dampers, gaps at the wall and brick fireplaces as well as the gas pipe penetration below manufactured fireplaces will let a lot of air into or out of the house.

We typically have negative air pressure in our homes. Unbalanced heating systems, dryers and exhaust fans all pull air out of our heated space. Additional heat loss through ill fitting attic access panels, older versions of recessed lighting fixtures, and poorly sealed exhaust fan penetrations, allow the warm air to escape through finished ceilings. This causes a vacuum that pulls cold air in through our plumbing pipe openings, floor register gaps and wall outlet openings. This results in hot air rising, which pulls colder air in. This is called the Stack Effect.

A cubic foot is roughly the volume of a basketball, so when a dryer can draw 200 cubic feet per minute (cfm), picture 200 basketballs worth of air leaving your house every minute. A good reason to open the laundry window a crack in order to prevent a vacuum drawing cold air from your crawlspace and attic, into the house and clean clothes.

So back to air sealing, prior to adding insulation, it is very wise to have someone seal all the various openings from the crawlspace and attic into your house. Think about the quality of air from these places, it’s not very good! All the more reason to seal them up. The exterior walls need attention too with doors, windows, chimneys, and fans providing air intrusion points.

Many of the gaps and openings are very accessible before we add insulation and are therefore less expensive to locate and block. Often there is very little one can do to better the attic if its already filled to the gills with insulation, limiting access and room to move.

DO IT YOURSELF TRICK for finding air leeks:

Close all of the windows and doors in the house and turn on all of the exhaust fans; kitchen, bathroom, and laundry fans as well as the dryer. Then start walking around the house checking the exterior walls, top floor ceilings, and bottom level flooring. Use some incense near the drywall penetrations, seams of dissimilar materials, windows, doors, and fixtures to see where the smoke indicates airflow. Professionals use blue painters tape and seal them as they go. This helps identify the places for corrections and increases the tightness of the house, making it easier to find the smaller openings. This is a great tool, unless your older home has too much air leakage to create negative air pressure to begin with.

HIRING A PROFESSIONAL CREW:

After you have tried this you may find that having a professional crew come in and do a blower door test makes sense. They use a strong fan to depressurize the house and locate the openings. Your money is much better spent if you have the same people doing the testing and also sealing things up as they go. Someone coming in to test and write you a report, followed later by a separate crew to seal things up, leaves much to be desired. They may not be able to locate all of the places or know if they sealed them well as they go.

Another tool that trained crews use is duct blasters. They pressurize our heating ducts to test and locate leaks in seams and fittings. Most homes with furnace ducting in their attics and crawlspaces are heating these uninhabited areas. Although the mice appreciate the expense, the result is a tremendous amount of heat loss from poorly installed and sealed furnace systems. If your furnace is located outside of the heated envelope of the house, chances are very good that there are gaps at the seams as well as uninsulated ducts heating your garages. This is not only a heat loss area but makes your heating system very inefficient due to different pressures inside and outside of the home. If our furnace is trying to force air into the house while loosing air into the attic and crawlspace, it ends up sucking air in from outside of the house to balance the demand of your return air system.

AIR QUALITY:

Another advantage of hiring a professional crew is that they should be trained to prevent  indoor air quality problems due to potential back drafting furnaces and water heaters. One of the worst situations is a gas water heater located in the laundry room. Back to the 200 cfm of air needed to dry the clothes– if the room can’t provide enough air it will pull exhaust fumes into the house from the water heater or furnaces. Remember to install those carbon monoxide detectors.

SUMMARY:

Although air sealing and insulation don’t initially seem to improve the appearance of our homes, we get a far larger return on our investment than we would buying those new windows that every magazine, newspaper and TV add tell us we need. As a result, our money can go a lot further. Start out with air sealing, move on to upgrading your insulation and then consider buying those new windows. You will be more comfortable and save far more money on your heating bills.

Now is a great time to act with the tax credits available. We can save energy, make our homes more comfortable, save money and lower our carbon foot print all at the same time. Most of these improvements pay for themselves in 3 to 5 years.

Things to remember:

  • always air seal prior to adding insulation
  • blower door testing is the best method to locate leak
  • we can save money, make our homes more comfortable and decrease our carbon foot print at the same time
  • a blower door test, with workers sealing things up as the go, is the most effective and less expensive than a separate test and report
  • care needs to be taken to prevent creating indoor air quality problems
  • tax credits are available to offset the costs

Do I Need a New Vapor Barrier in My Crawlspace?

Leave a comment

Q: You did an inspection for my clients in 2008.  They are selling it, and we just went through an inspection from their buyer.  There is clear plastic sheeting as the vapor barrier in the crawlspace and you had noted it as “satisfactory”.  Their inspector is telling them that it should be black 6 mil plastic.  Is there a code to be followed?  I wouldn’t think color would be an issue?

As always, your expert opinion is valued!

Diane

A: The early requirements for a vapor barrier in the crawlspace did not require black. We have learned, and the code changed, to require black to prevent organic growth under the plastic sheathing.

The home was built in the 80’s and the code requirement didn’t take effect, in most jurisdictions, until the mid 90’s. If the crawlspace doesn’t have high moisture issues, and is still dry, there is no need to change it out.

The clear plastic sheeting will continue to function well and perform its required and needed function, to prevent ground moisture from raising the crawlspace humidity level and migrating into the home.

It met the code at the time the home was constructed and if there are no new moisture problems it is fine and doesn’t require replacement.

How to Banish the Sewer Smell

Leave a comment

Q: Hi Steve, occasionally we get strong sewer fumes that seem to come from the basement bathroom. Any ideas what this could be? Any insight would be most appreciated.

Thanks, Ann

A: First thing that comes to mind is a dry shower drain. You said the bathroom would be used only for TV room use– if the shower hasn’t been used for a while, start there. When water in the drain’s p-trap evaporates, it allows sewer gases into the home.

All sewer drains have a p-trap = the U shaped drainpipe fitting we see below our sinks. These are intended to hold water and block the sewer odors from entering our homes. Toilets have them built-in, floor drains, showers and bath tubs have them below the floor level.

My guess is the shower is rarely used and the drain has dried out. (This can happen even faster in warm weather). Pouring a couple cups of water into the drain should re-charge the trap and block the smell. Keep in mind that all unused plumbing fixtures can create this same experience. The forgotten wet bar, the unused basement floor drain, or the unused washing machine drain connection…

A little bit of water should clear the air.