Since 1977 Wilkens Contracting Inc has been doing brick restorations in Toronto.
One could say “I’ve seen it all.” The following are articles written from first hand observation and information gathered by me.
The major cause of brick and mortar deterioration is basically moisture. The deterioration usually shows first (a) along the base of the walls, (b) in and below window sills, (c) by the downpipes of the eavestrough system, (d) porch walls and pillars and (e) in the chimney above the roof line.
The reasons are as follows:
(a) Before the early 1950s foundations weren’t sealed. the moisture in the soil sits right against the foundation masonry and tends to wick up the wall. The end of the “wick” is where the masonry tends to degrade most rapidly. Brick restoration and pointing is needed here to maintain the integrity of the foundation.
(b) The areas below the windows get a beating in the late fall and early spring. This is mainly due to snow accumulation on the sill and its slow melt from heat loss through the opening, saturating the sill and the bricks below. Added to this is the freeze/thaw which occurs when the temperature drops and rises and when the sun melts it on a cold day. Brick restoration and pointing is needed here to keep the moisture from getting to the inner wall.
(c) Over the years there have been times when the troughs were not cleaned and have overflowed. The down pipes are at the lowest points of the trough system so are the points that the water would spill over. If the down pipe is on the north side of the house it also has the problem of freezing solid in the winter. Snow melt, on a cold but sunny day, will tend to freeze in the down pipe and split the seams. When the ambient temperature rises it takes a while for the solid mass of ice in the pipe to thaw and the current run off will leak through the split seams onto the masonry wall and saturating it. Brick restoration and pointing is needed here to keep the moisture from getting to the inner wall.
(d) Porch walls and pillars wear more rapidly than the house walls because they are exposed to more weather and they don’t have the advantage of being dried out by the heat of the interior of the house. They get wet and/or saturated more often and then are subject to the freeze/thaw cycle. Brick restoration and pointing is needed here to maintain their structural integrity as well as aesthetics.
(e) Ah, the poor chimney. Chimneys really get the most wear and tear. Not only are they exposed to the elements no matter which way the wind blows but they also have to deal with temperature differentials and condensation.
In inclement weather they get saturated no matter what. Then the furnace comes on and dries them out. Then the furnace shuts down and they get wet. Then the furnace comes on and they dry out. Then the furnace shuts down and….you get the idea. Now imagine that happening over the span of your homes existence.
In the old days of coal there was really not a condensation problem. With the introduction of oil heating the stack (chimney exhaust) temperature decreased as the oil furnace was more efficient and less heart was going up the flue but with the outside temperature in winter being very cold there would be a bit of condensation in the chimney above the roof where it is totally exposed. In the 1950s terra cotta flue tiles were introduced to handle this problem. Then came natural gas heating. Now the stack temperature was very cool compared to coal or oil and condensation occurred a great deal more even with the terra cotta flue tile. Here the aluminum gas chimney liner came in to both prevent condensation due to the resizing of the exhaust path and also to keep any condensation from the bricks.
So over the years chimneys have taken the worst of it. Most new furnaces no longer use the chimney but wood burning fireplaces still do. Brick restoration,pointing or rebuilding is needed on chimneys to maintain their structural integrity, allow them to safely function and exhaust the products of combustion and to keep you home looking like it should look.
As a note, when having your chimney rebuilt many people are sold precast concrete caps. These are fine but were not in use until the 50s as well. On older homes Wilkens Contracting Inc. prefers to corbel the top of the chimney to maintain the period design. Many homeowners are told the reason for the chimneys wear was the lack of the precast cap which is simply not the case. The reasons are stated above. To verify this for yourself you simply need to go to an older part of town and look at the chimneys. These homes are older than most of the homes in Toronto and are still in good condition and were mostly have a corbel at the top. It is wear and tear that deteriorates the chimney, not the crown design. I think a corbel, in keeping with the design of your home, looks much better.
