The Ugly Truth about Brick Houses
It is nice to own a solid house made of brick but it is certainly wrought with problems.
For starters, where insulation is concerned, brick has an R value of 0.2. This means that our 8 inch thick walls with 1 inch of plaster has an R value of 1.8. The recommended insulation in walls is R-11. This means that the resistance to heat flow is pretty piss poor! In fact heat transfer is quite slow but it still occurs. The advantages in the summer are that our first floor stays relatively cool as long as the shutters are closed on the windows. Also, if it gets cold outside, it will be warmer inside for a few days. If you get a warm day or two though after a cold spell, well, the reverse is true. If you open the windows to warm the place up then you get condensation on the interior brick walls that are colder than the air that hits them. The outside temperatures this week have been as low as 10 degrees. The inside temperature on the first floor hit 32 degrees on Friday this week. If temperatures rise above this, it will take several days for the inside to catch up. It could be 60 degrees outside but will be 40 inside for several days and if I open the windows to let the warm air in then my walls will sweat and the acrylic paint will blister.
Another disadvantage is that if your gutters get clogged and water drips on the brick, the brick will suck up the water and transfer it to the inside plaster. This causes paint to peel. We have noticed that since we have bought the house and are slowly sealing it up that old paint is peeling where walls used to be continuously damp and wood molding is shrinking from drying out. This causes gaps between it and the plaster. Another thing to note is that houses built prior to 1920 or so had a high lime content in the mortar. Old brick is quite soft and mortar is supposed to be softer than the brick. Old recipes for mortar were varied and many had no Portland cement. I suspect ours was something like one part lime to 3 parts sand. Often the lime leaches out leaving just sand between bricks. New mortars are harder than old brick and should not be used unless you add lime to them. For my tuck pointing I have added about 1 part hydrated lime to one part masons mortar. It seems to be holding quite well. It is something people should be aware of though because using modern mortars will cause your old bricks to crack eventually. Many contractors who call themselves "masons" don't even know about adding lime to mortar so beware if you need to get a chimney fixed. They will coat it in a Portland cement mortar and ten years from now your bricks will be crumbling. I know because this was done at this place! Any way, whether or not you have a brick house, now you know the ugly truth!