September 7, 2010

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How to Determine Whether Your Flue Needs a Chimney Liner

August 13, 2010 By chimneyadmin Leave a Comment

There are many reasons why your chimney may need a chimney liner. The tiles in your flue may have cracked for any number of reasons. If these tiles are damaged in any way the chimney is not safe to burn and should be relined with a stainless steel liner prior to use. The clay flue tiles in the flue system

This liner has been cracked and must be replaced before it is safe to burn.

This liner has been cracked and must be replaced before it is safe to burn.

can become damaged in many ways. If a chimney fire occurs in your flue system the extreme heat may crack the flue tiles. The chimney flue is not intended to actually contain fire, only the products of fire which would be the gases that vent up through the chimney. If something causes a fire to start up in the flue system, say a bit of nesting is in the chimney and it catches fire, the heat can crack the flue tiles.

A shifting foundation may also cause flue tiles to crack. If the home is settling or the foundation shifts significantly it can cause a crack in the flue tiles. When there are cracks in the flue tiles the heat in the

flue system is able to reach combustible parts of the chimney. This is the reason that chimney relining must occur; it prevents fires in the flue system which can spread to the rest of the home. Chimney repair after a chimney fire is not cheap.

Your clay chimney liner has mortar joints in between each tile. If the liner is missing mortar joints the chimney cannot be burned until a liner is put in for similar reasons to those of cracked flue tiles. The missing mortar joints expose more of the chimney than should be exposed, making it more likely for any combustibles to combust.

The only real way to tell if your flue system has experienced any of these conditions, whether it be cracking or missing mortar joints, you must have your chimney swept and a video inspection of the flue system run. It is extraoridinarily difficult for a sweep to check out each individual flue tile for cracks or missing mortar joints by merely shining a flashlight in up the chimney. Using advanced chimney inspection tools, such as video cameras which are planted into small rods with lights, enables sweeps and homeowners alike to see what is going on in the flue system. Similarly, pictures can be taken using such equipment which can be used to make insurance claims if a chimney fire has occurred.

Another reason you may need to reline your chimney is if the chimney’s current chimney flue liner is too large for whatever it is venting. If you are experiencing draft issues or smoking problems, relining your chimney may be the way to go. An improperly sized flue may cause your chimney to not be able to draw properly. If you install a new stove or an insert it is generally required by the manufacturer and by NFPA 211 to have a chimney liner. If you are experiencing a draft issue or have a smoking problem you may be in a situation requiring a chimney liner.

Filed Under: Chimney Liners Tagged With: , ,

How to Clear a Blocked Chimney

August 11, 2010 By chimneyadmin Leave a Comment
This chimney cap will prevent a blocked chimney from occurring.

This chimney cap will prevent a blocked chimney from occurring.

Blockages in chimneys occur for a variety of reasons. Take, for example, a normal fireplace flue. If this flue was not capped by a chimney cap, it was be extremely easy for birds, squirrels, or other critters to climb into the chimney bringing large amounts of nesting materials with them. This nesting material can completely block your flue, preventing the chimney from drafting properly. This material is extremely flammable; flues are not meant to contain fires only the products of combustion. If this nesting material were to catch on fire and the flue were to contain this fire, flue tiles could crack and the entire chimney could catch on fire.

Always, always, always unblock from the bottom. Never unblock a chimney from the top. In cases of nesting material there are corkscrew attachments that can be put onto cleaning rods to actually hook into the nesting material and lift it out.

If you are dealing with a chimney that is venting two different flues, say the furnace and the hot water heater, the white wall that is between the two flues may buckle and block the flue system. This can cause these appliances to vent improperly. You may have a carbon monoxide detector go off if this is the case because often times the gases that are the products of combustion from gas appliances cannot escape the chimney. In this case you would unclog the flue from the bottom. You may need to widen the bottom opening where the appliance connects in order to successful unblock the flue system in this case. Signs that a white wall has collapsed would be the appliance immediately shutting off or the carbon monoxide detectors going off.

The flue is not properly unblocked until one of two things occurrs. First, if the flue has no bends or offset flue tiles, the flue is properly unblocked when you can tilt a mirror up the flue and see daylight (when the cap is removed, of course). If there is a bend or offset flue tiles, the flue is properly unclogged when you can run a sweeping rod the entire way up the flue system to the very top.

Clearing out a blocked chimney can be very expensive, especially if the sweep charges per hour and takes a long time to remove compact debris. The best way to avoid a blocked chimney is to install a chimney cap. This cap will prevent animals of all shapes and sizes from bringing any nesting material into your flue. This will prevent costly chimney repairs if a fire catches up in the flue system.

Filed Under: Chimney Cleaning and Sweeping Tagged With: , ,

The Top 3 Ways to Solve Chimney Leaks

July 10, 2010 By admin Leave a Comment

Chimney leaks frequently come from three common areas on fireplace chimneys. Chimney crown leaks, chimney flashing leaks, and brick chimney leaks. Different factors affect a chimney’s ability to resist water penetration such as the age of the chimney, the type of construction materials used and the way it was constructed. In this article I’m going to reveal some specific problem areas and how you can solve your own chimney leaks.

Chimney Crown Leaks

chimney crown repair

Using Brushable CrownCoat for chimney crown repair

First off, the chimney cap or masonry chimney crown. Over time, chimney crowns can crack or break off, allowing water to soak in and come inside the chase. This water can run down the chimney and absorb into the inside of your house. Additionally, crowns are supposed to be made of concrete, but are frequently made from mortar instead to save time and money.

The problem is that mortar is not as dense or as strong as concrete and is more likely to absorb water. If the crown is in too bad of shape, you may need to replace the crown. That can usually run anywhere between  $500-$2,000.

If there are some severe cracks, but no missing pieces off the crown, my chimney sweep crews usually use a product called CrownSeal. It’s a flexible elastomeric product that you can trowel on over the surface of the crown. It fills in the gaps and seals the crown, preventing chimney water leaks. CrownCoat works even better for crowns with smaller cracks and in slightly better condition. It’s easier to apply and it dries faster. Read more about chimney crown repair in our article “Chimney Crown Repair“.

Chimney Flashing Leaks

chimney flashing leaks

Using FlashSeal to repair chimney flashing leaks

Chimney flashings are another potential source of water leaks. Where the chimney meets the roof line is a particular weak spot for water penetration because as rain water runs down the roof, it gathers and runs off right onto that joint.

Over time, as the chimney flashing deteriorates, water can gradually begin to seep into that joint and into your house, ruining drywall, causing wood rot and mold growth.

There’s a product called FlashSeal that you can apply on top of the chimney flashing to seal up this joint. There’s a mesh fabric that can also be applied underneath that makes it even stronger.

Brick Chimney Leaks

brick chimney leaks

Use ChimneySaver water repellent to fix brick chimney leaks

The last problem area is the bricks and mortar joints. There are many different types of brick out there. The softer and more porous the brick, the more likely it’s going to leak. Mortar joints are another problem area. Many times, the mortar mix is made with too much sand, causing it to soak up water like a sponge.

Also, many times the mortar joints are struck (packed in with a special tool) too shallow, causing water to be able to quickly absorb and pass through the thin layer of mortar. To prevent water penetration in brick and mortar joints, try a waterproofing product called ChimneySaver. It’s a breathable water repellent that you spray on your chimney with a pump-up sprayer. It actually forms a chemical bond with your masonry about 1/4″ below the surface, making the masonry repel water for 5-10 years.

If you have cracks in your mortar joints that are wide enough to stick a credit card in, you can use a product called CrackMagik. It’s designed to fill in the cracks that are too large for the water repellent to fill. Most water repellents can fill hairline cracks. Any bigger cracks need to be filled either with a mortar crack chimney repair product such as CrackMagik, or for more severe cracks you will need to tuckpoint the mortar cracks with new mortar.

By protecting the chimney crown, flashing and brick and mortar, you’ll save yourself the expense of chimney water damage and eventual chimney replacement. Water damage causes over $1 Billion in damages every year. In most cases this damage can be avoided by a little preventative maintenance once every 5-10 years.

Filed Under: Chimney Crown Repair, Chimney Flashing Repair, Masonry Chimney Waterproofing, Mortar Repair Tagged With: , , ,