Chimney & Fireplace Leaks
Brick chimneys, stone chimneys and fireplaces what do they all have in common? Over time most require some type of maintenance to keep a water tight seal. Many homeowners at some point in time will find a water stain on or around the homes fireplace caused by leakage of the fireplace flashing system.
One of the first items your professional roofer will want to check is the step flashing and counter flashing around the base of your chimney on top of the roof. Clearing off old dried out caulking and roof cement around the chimney base is one of the first items on the check list. Once this is done your roofer will want to inspect the metal flashing for cracks and tears replacing as needed. We recommend installing a high quality Flashing Cement as opposed to plain roofing cement on any area that require sealing. Asphalt roofing cement has it’s uses but a good quality Flashing Cement is far superior in our opinion when it comes to sealing many types of roof flashing. These simple steps can fix many chimney leaks.
I said many and not all because quite a few chimney leaks have nothing to do with the flashing around your chimneys base. Lets start with brick and stone chimneys. These types of chimneys consist of brick and stone held together with cement. They also have a cement cap on the very top of the chimney that has a crown to it for shedding water. Over time the mortar joints and the cement cap can develop cracks. These cracks let water in which can run right behind the best chimney flashing and into your home. Many chimneys will need to be pointed up and recapped by a qualified masonry contractor if these cracks begin to appear.
We once received a call for leakage on a very large brick chimney. This home owner just replaced the entire chimney with all new brick and mortar. They also had the mason install a new cement chimney cap on top of this new chimney. The homeowners were quite perplexed as to what could be causing the leak since not only was the entire chimney new the roofing on the home was also relatively new. We went out and did a complete inspection of the roofing and flashing systems around the chimney and found them to be in good condition. We suggested they allow us to hose down the chimney starting at the base of the chimney and working our way up. They agreed and we dispatched one of our staff into the attic cavity to identify water leakage as soon as it was visible while the other team member hosed down the chimney outside.
Members of our team hosed down the chimneys flashing system with no leakage visible. We then waited for the chimney to dry off for a time before hosing down the brick and mortar as to give any slow leak a time to appear. As suspected no leak appeared and we then proceeded to hose down the new brick and mortar. After about 20 minutes of hosing down the brick water appeared on the brick inside the attic cavity. The mason was to say the least not pleased nor completely convinced that the brick and mortar was the culprit. The rain was being absorbed by the porous brick and during long periods of rain water would eventually show up on the brick face of the fireplace inside the home. The homeowners decided to have the entire exterior of the brick fireplace sealed and that eliminated the problem (note some claim sealing brick can cause damage to the brick check with a qualified mason before doing anything listed here).
Now if your chimney has wood or cedar siding on the exterior here are a few things you may want to have a professional roofer check besides the obvious flashing which should always be one of the first items checked. Cedar clapboard siding some times will have knots in the wood that either come loose or completely fall out. Both of these can cause water to run behind your roofs chimney flashing. Another problem that can occur with this type of siding is splitting. We have found many a cedar house with siding that looked sound but under closer examination had splits. Some of these splits were right under the laps of the siding and can’t be seen unless you look up under the siding. Water can once again get behind your roofs chimney flashing if rain hits the side of the chimney with split wood siding. T-111 siding or vertical wood siding can leak at the lap joints so carefully have a professional check these types of siding. Have your professional also check the wood corners and chimney tops to make sure everything is sealed correctly as wood siding material tends to open up at the joints causing opportunities for water infiltration.
These are just a few items you may want to have inspected if you are experiencing a chimney leak or are considering replacing your roof. Please feel free to contact Maryland Shingle Roofing & Siding Contractors by e-mail or the numbers below if we can be of any assistance or you are in need of new roofing.
Return to Leak Diagnosis Page Click Here