Solid Brick Wall Vs Cavity Wall (floors, how much, roof, dishwashers)

[tar21]

They didn't start using cavity walls until about the 1930's, allegedly to help prevent dampness and mold from transferring inside. But before that for thousands of years they used solid brick walls. How much of a problem did solid brick walls really have with dampness and mold transferring to the inside walls? It seems like it there was a problem they would have done something sooner.

[Ed Ferris]

What they did is fur-out the interior walls. Lath and plaster separated from the brick by two inches. Plaster directly on brick is called "render" (at least here in Indiana) and it does have a record of getting wet and falling off.

[loves2read]

We have house built in late 70s in Fl mid Gulf Coast
It is Cement Block exterior--and cavities are not filled in I believe
The rooms w/exterior walls have lath and Sheetrock--no framing ---
different type of electrical boxes on those walls as well because of shallower depth necessary

Can't have a shower niche on CB wall which made us rethink how we did our bathroom remodel/shower design...

[just_because]

Originally Posted by tar21

They didn't start using cavity walls until about the 1930's, allegedly to help prevent dampness and mold from transferring inside. But before that for thousands of years they used solid brick walls. How much of a problem did solid brick walls really have with dampness and mold transferring to the inside walls? It seems like it there was a problem they would have done something sooner.

Techniques evolved when they evolved and it's not logical to conclude that because it took so long for cavity walls to develop that dampness was not an issue. Here are some of the issues:

-walls get cold and will attract moisture from the room leading to wetness
-solid walls are much more difficult and expensive to insulate (need to be internal or external)
-brick and mortar gets more porous as it ages making the problem worse as the building ages
-wall mounted heat sources will 'leak' heat directly out the walls as masonry will conduct heat very well
-wet/moist walls are especially poor insulators
-building must breath, therefore the materials that should be used are limited- e.g. Breathable paints, no drywall on exterior walls, lime plaster and mortar, etc. Often these things will have been ignored in renovations at different points over the long life of the building so difficult to judge
-bad moisture handling over different owners/renters/vacant periods may have led to damp causing wood rot in timber beams - not uncommon for such damage to be discovered during renovations increasing costs of everything
-closets, cupboards and anything against the exterior walls that restricts airflow can create even more issues of damp and mold- even hung pictures and furniture against the walls
-nobody likes drafts but drafts are needed to dissipate moisture from the home. Block too much of the drafty windows, floors, etc with modern solutions like new windows and sealants and you likely will create different problems
-some modern solutions like exhaust fans help but modern expectations and lifestyles make problems more apparent than before - more clothes washing and drying, more showers, dishwashers, more intense cooking activity, etc

All that said, millions of people live in solid wall construction houses and survive nicely. Just do not underestimate the differences with modern construction. Your expectations need to be adjusted accordingly.

[Meemur]

Originally Posted by just_because

All that said, millions of people live in solid wall construction houses and survive nicely. Just do not underestimate the differences with modern construction. Your expectations need to be adjusted accordingly.

I haven't seen any solid wall construction houses in years! Will they meet the new earthquake codes?

[Ralph_Kirk]

Originally Posted by just_because

Techniques evolved when they evolved and it's not logical to conclude that because it took so long for cavity walls to develop that dampness was not an issue.

We had concrete block constructed homes in the Philippines, no kind of interior furring--just paint on the inside of the black. However, the houses were drafty as heck. In some construction, the exterior walls were short of the roof with a screened open section at the roofline.


Even with darned near free airflow, we still got mildew on the interior walls during the monsoon season.

[just_because]

Originally Posted by Meemur

I haven't seen any solid wall construction houses in years! Will they meet the new earthquake codes?

Ummm no....I would not expect them to meet any modern codes.

Construction differs around the world but I would expect that pre-1930s or 20s masonry construction would usually be solid wall just as the OP says. You can often tell from the brick patterns. Lots around in masonry victorians. Very solidly built but moisture handling and limited insulation potential are the Achilles heels.

[Ed Ferris]

Masonry walls are damp because of their thermal mass. They cool during the night and then on warm humid days are cooler than the surrounding air, so moisture condenses on them. You should not insulate a furred-out brick wall. What's important is to insulate the attic floor so the building doesn't act as a chimney. The heating bills in brick Victorians are no worse than in any other construction (except specially ultra-insulated) once the attic is insulated and the drafts are stopped. Brick veneer construction on wood studwalls goes back to Victorian days. It was recommended by George F. Barber. Unfortunately, the condensation on the interior face of the brick will rot the studs eventually. I have seen a house in Woodruff Place that had to have the walls rebuilt because of this problem. It was said, back then, that a week of driving rain will soak through a foot-thick brick wall. I've never lived in a climate that would test that statement. Ro-Lock construction set the bricks on edge and left air spaces inside the wall. I've seen only one house built that way and don't know whether it has any practical insulation value.

[just_because]

Originally Posted by Ed Ferris

Masonry walls are damp because of their thermal mass. They cool during the night and then on warm humid days are cooler than the surrounding air, so moisture condenses on them. You should not insulate a furred-out brick wall. What's important is to insulate the attic floor so the building doesn't act as a chimney. The heating bills in brick Victorians are no worse than in any other construction (except specially ultra-insulated) once the attic is insulated and the drafts are stopped. Brick veneer construction on wood studwalls goes back to Victorian days. It was recommended by George F. Barber. Unfortunately, the condensation on the interior face of the brick will rot the studs eventually. I have seen a house in Woodruff Place that had to have the walls rebuilt because of this problem. It was said, back then, that a week of driving rain will soak through a foot-thick brick wall. I've never lived in a climate that would test that statement. Ro-Lock construction set the bricks on edge and left air spaces inside the wall. I've seen only one house built that way and don't know whether it has any practical insulation value.

I don't know brick veneer on stud walls as the victorians in these parts have structural masonry walls. In theory wood lathe on interior plaster won't rot if the plaster is lime and can dry out from the inside as well as outside. Hence why breathable materials are so important. I do differ on the heating bills. Although attic/loft insulation is important, you walls are completely uninsulated and unless retrofitted (at great expense) the ground floor floors are also thin wood with big gaps in a 'proper' Victorian. Carpet helps but it's not enough, it restricts 'drying ' airflow in the crawl space and is often not what people want for aesthetic reasons. Oh the practical joys of a 115 year old masonry house.

[MrRational]

Originally Posted by loves2read

Can't have a shower niche on CB wall ...

Not directly against the block... but with a moisture barrier you should be able to.