[peter101]

Mysterious white triangle lines on both side walls around my brick chimney.

After winter I found there are white triangle lines on both side walls around my brick chimney. After raining (no mater heavy or light rain) for 1-2 hours, the brick wall on both side of the chimney will have a deep color triangle area larger and lower than white triangle lines. But, I have touched the deep color area and did not fell water on the brick.

When it does not rain, the deep color triangle area will be fading out and can only see it 50 meter away. Till now, we have rain every week.


Please help me to find possible reasons?

Thank you.

 

[Clemsig07]

I've seen your pictures a few times and I'm really interested to find out what's going on.

Which way does the sun move around your house? What is on the other side of the wall up there? Do you use your fireplace? What part of the country are you located in?

I don't ask these questions because I think I know what's going on, but I think some more information might help some other people figure it out.

Good Luck!

 

[seeyou]

I've seen your pictures a few times and I'm really interested to find out what's going on.

Which way does the sun move around your house? What is on the other side of the wall up there? Do you use your fireplace? What part of the country are you located in?

I don't ask these questions because I think I know what's going on, but I think some more information might help some other people figure it out.

Good Luck!

Boy, I hope it's moving clockwise or else we're all in trouble...........

 

[seeyou]

You've got some source of moisture at the chimney. It's likely the flashing or the chimney top. I'd bet on a flashing issue. Got any close up pics of that?

 

[epson]

That my friend is called efflorescence and it is formed by water within the construction material. In your case brick, the water reacts with the natural salts contained within them and the mortar by dissolving and then it is brought to the surface and when evaporated will turn into a white fluffy powder.

 

[peter101]

You've got some source of moisture at the chimney. It's likely the flashing or the chimney top. I'd bet on a flashing issue. Got any close up pics of that?

The chimney is for oil furnace and not used for 7 years.
The other side of the wall (inside the house) has not water.

After winter and in early spring ( I am in a very cold area), I found these white lines. Then the dark color area appears after each rain. I found and fill two 1'' gaps betwee saddle and chimney wall. An I seal all flashs and singles around the brick chimney with roof cement.
It does not solve the problem.

The chimney joints are ok. One day before a rain I covered the chimney with plastic from top to buttom.
It does not solve the problem. Next day after the rain I opened cover and found the plastic and some chimney bricks had water on them. And I am sure the rain did not enter the cover. The bricks 1-2 feet to the gutter has
more water.

Part of the gutter is next to chimney.

I also run water 4.5 hours from the top of saddle around the chimney 1 foot to simulate a mild rain. I can not reproduc the dark color area on my brick wall.

 

[epson]

Two ways of cleaning this off: 1) let nature take its course with weathering of the surface and it come off. 2) A good scrub with a dry stiff brush will remove the worst and then follow with a soft brush to remove the salts away from the wall entirely.

 

[peter101]

Thanks for advices to clean, but I still not find the sources.

Two ways of cleaning this off: 1) let nature take its course with weathering of the surface and it come off. 2) A good scrub with a dry stiff brush will remove the worst and then follow with a soft brush to remove the salts away from the wall entirely.

Thank you for advices, but if I don't find the sorces it will appears again.

Now I have cavered the chimney and it flashs and saddle with plastic, but I still get the deep colored area after the rain. It is light than before It may be due to one week sunny day the water inside the wall evaporats a lot or may be due to my covering the chimney.

What I should do now to find the leak or sources of water?

 

[seeyou]

Thank you for advices, but if I don't find the sorces it will appears again.

Now I have cavered the chimney and it flashs and saddle with plastic, but I still get the deep colored area after the rain. It is light than before It may be due to one week sunny day the water inside the wall evaporats a lot or may be due to my covering the chimney.

What I should do now to find the leak or sources of water?

Uncover the chimney and get on the roof with a hose. Start running water on the roof just above the chimney for 30 mins or so. Observe the brick. If nothing shows up, set the hose so it's spraying on the flashing for 30 mins or so. It's most likely a leak on the roof or at the flashing.

Take us some pictures of the back side of the chimney/flashing/roof.

 

[hammerlane]

Do you notice after a rain that the brick on the chimney is wet and stays damp for a few days before it drys out? Most people do not realize that brick and mortar are porous and will absorb moisture. I had the same problem with the efflorescence appearing on the chimney. My chimney faced the west side of the house and was completely exposed to the wind driven rain.

My remedy was to apply a water repellent from Prosoco called Weather Seal Siloxane PD(the PD stand for pre-diluted). After this is applied and the chimney gets wet, the water runs off the brick like a newly waxed car.

See the data sheet here:
http://www.prosoco.com/Documents/getfile.aspx?filekey={BE74BFA6-F2AB-4ACF-9F51-EBDCC35C2FB9}

But because the repellent will not prevent water penetration through
structural cracks, defects or open joints I also spent a few hours paying attention to all the mortar joints....both head and bed where there were any cracks in the mortar. So I bought and brushed on a product from Saver Systems called ChimneyRx® Masonry Crack and Joint Sealant.

http://saversystems.com/chimney-products/crack-and-joint-sealant

If you decide to purchase the ChimneySaver Masonry Crack and Joint Sealant I do not know where you live but I recommend buying from Duval Paints at:
http://store.duvalpaint.com/chimney-rx--maintenance-products-c4.aspx

I bought from him and there was a slight problem with shipment. Some product spilled and they quickly remedied the issue.

 

[Windows on Wash]

I would be suspect of the chimney flashing to start with.

After that, I would recommend sealing up all the brick as mentioned previously.

 

[hammerlane]

I should of also mentioned the chimney crown. Saver Systems also has ChimneyRx® Trowelable Chimney Crown Repair which is an elastomeric coating that forms a flexible waterproof membrane over the surface of the crown. It is specifically formulated to repair and protect chimney crowns from water intrusion. It can also be used for a variety of horizontal and vertical exterior waterproofing applications. It dries to a natural concrete/mortar appearance.