Fireplace Problems

"Carl,
We have a 10 year old vented gas fireplace. The fireplace, which has been cantilevered out from the foundation, sends the exhaust up a chase which extends several feet above the roof line. The chase is OSB covered with felt paper and cheap vinyl siding. Underneath the chase from the outside, you can see the uninsulated OSB bottom. The space directly underneath the fireplace is also uninsulated (between the first floor's joists).

I can see un-papered batting under and around the firebox (top and bottom louvers.) I also hear intermittent "pings" when it rains, as it has done steadily here for the past four days. I think it is rain drops hitting the top of the fire box.

Last January, there was an incredible draft coming through the fireplace, which made it impossible to raise the thermostat on the first floor. In order to heat the first floor, we covered the fireplace with taped Hefty bags which were most unattractive, but mildly entertaining since the bags moved in and out and gave the fireplace a life of its own.

We had two fireplace companies take a look and both recommended that we install a new direct vent fireplace (Mendota brand) and vent out the back, insulate the chase, cap the top, etc. This would require us to remove and re-cut our granite surround, which consists of one giant piece (no mantle). The full replacement would cost approximately $10,000 (tear out, install, granite, electrical, permits, etc).

I have scoured the internet but have come up empty with respect to finding a less expensive, less invasive, option. My wife would like to forgo the Hefty bags this winter.
L.C."

Hi L.C.

I think you have 3 separate and often concurring problems.
1. Downdrafting.
2. A poorly constructed, non-insulated, and drafty chimney chase is acting like an “open window”.
3. A water leak(s) in the chase.


(Diagram A) Courtesy of fireplacesnow.com

I believe your most serious problem is “Downdrafting”.
Downdrafts force the hot exhaust gases that are trying to flow up and out of your fireplace back down the flue liner and into your living area.

Downdrafts occurring when the fireplace is in use will cause carbon monoxide poisoning!

If you don’t already have them, get yourself several carbon monoxide detectors for your house.

Downdrafting: Downdrafting is usually caused by a chimney that is too short. That puts the flue opening directly in the path of wind vortexes. Wind vortexes are created as wind passes over roof ridge lines, trees, mountains, etc. The greater the velocity of the wind, the greater the vortex. This vortex wind creates downdrafts in your chimney flue.

(Diagram B)

The minimum (One often needs to go even higher) height a chimney should be is 2 feet above any roof surface or obstacle within 10 feet of the top of the flue. (See Diagram B)

Your chimney may be too short. If so, another section of flue would raise the height of the termination cap 3 feet, and I think that will help ward off down drafting, or

Courtesy: NorthlineExpress.com
You cold replace the termination cap with a down draft proof one (see more styles at Northline) or do both, raise the height and recap.

2. Drafts: The chase appears to be poorly constructed and is probably the cause of severe drafts around the firebox inside your home. These drafts are not to be confused with the down drafting problem.

I would have the vinyl siding removed (carefully, so that it can be reused and reapplied), have several of the OSB panels removed so that the chase can be properly fire stopped (see image), the chase insulated, the firebox chalked with fireproof chalk from behind for draft prevention and then, put the chimney chase back together and have the chase wrapped with house wrap (such as Tyvek) to keep the wind out, then reside with the vinyl siding.

3. Water Leaks: You have a leak (s) in the chase that is evidenced by both the photo of the underneath of the chimney chase and the “pings” you hear. The photo shows water damage (rot) and shows that the leak has been occurring for awhile.

The leak (s) may be in the chimney chase itself or more likely, at the top of the chase where the chase cap (called pan flashing in the diagram) may have rotted away.



The cap appears to be made of galvanized metal and galvanized metal doesn’t last that long before it starts rotting away.
If you replace the cap, use stainless steel or aluminum.
The chimney termination cap collar could also be leaking. (See diagram A)

The water leak could also be coming from the area where the roof meets the chase.
There is supposed to be a saddle (also called a cricket) that sheds rain water away from the chase (see image below).

Courtesy: Licitra Roofing

You should hire a LOCAL professional, such as a Professional Home Inspector, Home Builder (General Contractor), or an Architect to look at these problems (and any I may have missed) and help you make decisions as to the best course of action. This should not be too expensive.

I don’t think that the cure for these problems, even if you had to fix all of them, would be anywhere near the cost of replacing your fireplace. A good carpenter for the chase work (including adding insulation) and a good HVAC contractor (for the flue, cap, pan, firestop and adding an additional 3 foot section of flue if necessary) should be the only people you need to hire. The cost of insulation and additional flue parts, and even a new pan flashing and termination cap shouldn’t be too bad.

Good luck,
Carl

Buying Land - Buildable Lot or Not- That is the Question

"Dear Mr. Heldmann,

Your book, Be Your Own Contractor, appears to have one blatant omission. On page 17, you write:

Is it a buildable lot? This is the most important question to ask when deciding to buy a building site, and your local building inspection department is responsible for answering it in the form of a building permit. They will only issue a building permit if the property can be considered a buildable lot. Be sure to check with your local building inspection department before you purchase your site.

So, you're saying that I should retain an architect, survey the lot, test the soil, design a structure, have the plans reviewed, and see if a building permit is issued for my dream house, all for a lot I do not even own.

My city requires a site plan, floor plan, foundation plan, details where necessary, elevations and other plans, all submitted by a licensed architect, before issuing a building permit for new residential construction.

Even if a lot is buildable, a permit might not be issued for the design I want.

I'm obviously missing something here, and your book does not appear to explain it.

Chris"

Lot with a small building envelope

Hi Chris,

Buying land is one of the most important components in building a home.
Besides accounting for 25% or more of the total cost of building, all real estate boils down to location, location, location. It is important to know as much as possible about the process of buying land.

When I wrote "Is it a buildable lot" I meant, will the construction of a home will be allowed IF, and only if it meets all the requirements, restrictions, and criteria of the local building inspection department, zoning department, health department, etc.

Lots or building sites in general, even acreage, are deemed ““un-buildable” for any of the following reasons:
• Unsuitable for a septic system
• Water tables have been proven to be unsuitable
• NO water available
• Inadequate road frontage
• Too steep for safe construction
• In a flood plain
• Too small to qualify for a home site
• Possible endangered species habitat
• Zoning may not allow a residence there.
• Been used as a toxic dump site at one time,
• There may be some mineral deposit there that is hazardous, such as asbestos, radon, etc.

However, even if a lot is deemed buildable, it may not be buildable for you because, as you say in your second to last sentence, “Even if a lot is buildable, a permit might not be issued for the design I want.” In other words, it may be “buildable”, just not “desirable” for you, or for your project.

But someone can and probably will find a suitable house plan for that lot.

I found a “buildable” lot that was undesirable because it had so many "easements" and “setbacks” on it that the space left for a house (called the “building envelope”) was considered insufficient by other builders to build a house comparable to the neighborhood. (See survey above) With a lot of planning effort on my part, I made it work! The house sold in the framing stage!J

Before you, as you say, “retain an architect, survey the lot, test the soil, design a structure, have the plans reviewed, and see if a building permit is issued for my dream house, all for a lot I do not even own”, you can talk to the building inspection department to find out FIRST if it is it is a “buildable” lot.

Then talk to them (You are NOT applying for the Building Permit at this time) as to what requirements or criteria that must be met for an individual’s house plan. (They are there to help believe it or not.)

They may require that the house face a certain direction. When a lot is a corner lot, this is often a point of contention. You may be allowed to apply for a variance.

They may require a certain percentage of the lot’s surface area be left permeable for proper drainage and you have plans for extensive paving.

They may have other guidelines for house design and/or house placement on the lot. Ask them!

Another source of placing restrictions on what you can and cannot build are "Restrictive Covenants", also called "Deed Restrictions" because they are recorded with the deed when they are made by a previous owner of the land. They can be quite restrictive, and they are legal and binding as long they don't discriminate.

Some examples of deed restrictions are:

• What size house can be built.
• What colors the house must be or not be.
• Which way your garage door must face.
• That you have to have a garage door.
• Driveways must be of a certain building materia.l
• What style of home must be built and/or what kind of siding must be used.

Many, many other restrictions are often found and will be a subject I will be treating in the near future.

By the way Chris, the seller should provide a survey of the land at their expense. (There probably already is an existing survey.) The seller should bear the cost of a soil analysis as well.

Chris, thanks for writing and helping me expand this critical subject matter.

Best of luck,
Carl