10-2-3 Rule Older Home

[palmettoinspect]

What do ya'll comment about when inspecting older homes with wood burning masonry chimneys that do not comply with the 10-2-3 rule?

Does anyone know exactly when the 10-2-3 rule came in affect?

I've got a 1966 home where the chimney is about 12-18" out the peak of the roof.

Thanks,

Kiel

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[Jim Katen]

What do ya'll comment about when inspecting older homes with wood burning masonry chimneys that do not comply with the 10-2-3 rule?

Does anyone know exactly when the 10-2-3 rule came in affect?

I've got a 1966 home where the chimney is about 12-18" out the peak of the roof.

Thanks,

Kiel

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I wouldn't call 1966 "older."

My 1911 code for the City of Portland contains a rule that's quite similar. It requires the chimney to be 5' higher than a flat roof, 2' higher than a ridge, and 3' higher than a ridge if it's within 10' of the ridge.

The overwhelming likelihood is that the chimney in your picture was supposed to be higher when it was built.

That said, what possible difference does a 1966 rule have here? Is someone going to say, "Gee, since it was required in 1966, I'd better fix it?"

[Chad Fabry]

Realtor: You're so lucky! most people have to remove three feet of chimney to rebuild from the roof line up!

[Jim Baird]

10 and 2 being irrelevant at the ridge, my WAG on this chimney is that the brick there look so rotten and the mortar joints so new, that two feet of height and one piece of liner may have been removed at some point in time.

The roof line has a funny break just down slope, or is that just a digital distortion?

[palmettoinspect]

Thank you all for the replies. If I'm understanding you correctly you all wouldn't make a big deal of it given its age?

Jim,what you're seeing are two different roof lines that look like one in the picture.

[kurt]

.......my WAG on this chimney is that the brick there look so rotten and the mortar joints so new, that two feet of height and one piece of liner may have been removed at some point in time.

My thoughts exactly, and they may not have gone down far enough. The whole thing looks mushy.

Also, that crown is pathetic; calling it a crown is granting legitimacy....it's a mortar pile on top of shitty brick.

[palmettoinspect]

.......my WAG on this chimney is that the brick there look so rotten and the mortar joints so new, that two feet of height and one piece of liner may have been removed at some point in time.

My thoughts exactly, and they may not have gone down far enough. The whole thing looks mushy.

Also, that crown is pathetic; calling it a crown is granting legitimacy....it's a mortar pile on top of shitty brick.

Man! That crown actually looks good for around here lol!

Check out the side of the home with the brick over the roof line and the lovely flashing!

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[kurt]

Shameful.

Good for business, though....[:-angel]

[Hearthman]

The 3-2-10 rule dates back nationally to at least 1927. This chimney and the supporting pics show what appear to be soft fired bricks but definitely not SW or Severe Weather grade bricks intended for exterior use directly exposed. Note the salmon colored "Easy Bake" bricks, which are like sponges. Now note the hard Portland cement-based mortar. This mortar is waay harder than these chalky bricks which causes the destruction of the bricks from differential expansion along with freeze-thaw damage.

Rebuild the chimney from the attic-up meeting the code height. The flashing could then be properly executed with the counterflashing let into the mortar joints held with mortar-no nails or caulk but floating above the step flashing.

This type of brick used on modern houses is often the result of builders being suckered into reusing old salvaged bricks. Such bricks should be laid in lime mortar and are suitable for interior use only.

Once the chimney has been properly rebuilt, I would recommend treatment with ChimneySaver water repellent. It is the only one I know of which meets the BIA recommendation for 100% vapor permeable or not at all. Typical "water repellents" rely on solids to seal the pores much like varnish. CSS changes the electrostatic charge to like poles with the water droplets while allowing water vapor to pass. It protects small cracks. Used by most chimney sweeps around the country successfully since '87. Junk like Thompson's will ruin masonry by trapping water inside.

HTH.