Why would a chimney be leaking water into your home? How to fix water coming down a chimney into your home?

Do you have water coming down your chimney into your fireplace or living room? To avoid rot damage or damage to appliances such as a fireplace insert, your water issue should be fixed ASAP. There are several areas of the chimney, or roof where water might be coming from. Let me tell you where the water might be coming from and how to fix it.

From the very top of your chimney, there is something called a Rain Cap. These are metal caps that rest on top of your terracotta flue liner and they prevent rain water from flowing down your flue liners into your fireplace or home. If you have a wood burning fireplace, it's purpose might be a spark arrestor as well. If this metal cap is relatively flat, or slopes inwards towards the centre of your flue liner, water will pool there, and you might eventually have a leak. The best way of fixing this is to make sure this cap is sitting level and no part of it is sloping the wrong way. You may have to bend it or you may have to install a new rain cap. Also in order for it to sit and stay where you want it, you may have to caulk it to your flue liner so it doesn't move.

Below your rain cap, is your chimney cap, or crown. If you do not have a concrete or metal cap, instead you have a build-up of brick and mortar, this may be where water is penetrating your home. A proper cap should be one solid piece and not be made out of mortar that can deteriorate. A cap should overhang a chimney's face by 3 inches and have a drip edge at the bottom of it 2 inches or more away from your chimney. Two places a cap must be caulked is, where the cap encircles the flue liners, or anything that pokes out of the top of it, and in the case of a concrete cap the bottom of the cap must be caulked where it meets the face of the brick. Polyurethane sealant must be used for this.

Below your cap is the brick that make up your chimney. If there are holes in the joints especially on the roof side of the chimney where snow builds up and then melts, water may enter your home there. It is important to fill in any missing mortar from joints not only to inhibit water penetration but to prevent damage to the brick.

If your chimney is wide, and the slope of your roof heads towards your chimney you should have what is called a saddle roof. A saddle roof prevents snow or water from building up behind your chimney by adding sloped surfaces on the roof side of your chimney.

Where your chimney goes through your roof there should be flashing. The best kind of flashing for chimneys is a flashing that goes completely through the face of the brick or is slighlty imbedded in a "reglet" in the brick. Often times chimneys have flashing that is just butted up to the face of the brick and the top is either tared or caulked. If your chimney is letting in water you may want to cut a reglet or a notch into your chimney just above your flashing and slip in a piece of L shaped metal into this notch that is bent to go over top of your flashing. You will have to caulk this metal in place.

Another reason your chimney might be leaking is condensation. The heat from a well used fireplace meets the cold air from the top of your chimney and condenses into water. There are many reasons why this is happening. All reasons are due to either a bad designed chimney, an older chimney, or a poorly constructed chimney. Your chimney may not have a proper flue liner in it which aids in the draft and refractory characteristics of your chimney. When your chimney is built the mason also must take care to leave a space between your flue liner and the rest of your chimney for insulation purposes. For a good draft and for air to flow down and up your chimney properly you need to have what is called a smoke shelf, which is a carefully constructed round shaped shelf just above your fireplace which diverts any air rushing down your chimney back upwards. Also for draft purposes the higher your chimney is the better, so the air flow over your roof doesn't effect your chimney. Good circulation in a chimney goes a long way to prevent condensation buildup.

If you have any problems with your chimney, and live in the Ottawa area, don't hesitate to contact Tundra Masonry for a free estimate!