Margot G asked:

Dec 13, 2016
If a chimney needs rebuilding who do I look for? A roofer or a stone mason?

Ryan Gregory answered:

Dec 14, 2016

Both, more than likely. The mason should replace the masonry products and the roofer should work with the mason to achieve a regletted counterflashing and flash the roof under counterflashings.

Margot G asked:

Dec 13, 2016
If a chimney needs rebuilding who do I look for? A roofer or a stone mason? My home is 59 years old and has a leak somewhere around the chimney that has been difficult to locate and stop permanently. It has cracks in the mortar on the side and top crown as well as some missing mortar. The flashing has been "fixed" with tar or roof caulk several times. Is it normal to need a removal and replacement of the chimney mortar after some period of time?
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Dec 13, 2016
What is the temperature range for installing roof shingles
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Oct 10, 2014
black spots on the roof. can you tell me what is the cause of this? have lived in this house 12 years and have had no problems. what can you do to clean this?

kathleen Palmer answered:

Nov 10, 2014

Hey Terry, 

Black spots on the roof usually form do on the Northern facing side of the home because it has less direct exposure to sun light. 

Blue-Green algae is usually what the black spots are, however, depending on the age of the roof, sometimes the loss of granules also shows black streaking, which can be a sign that the roof is nearing the time for replacement.

There are products that can be used to clean the algae off of the shingles, but most require the use of a low pressure power washer to help strip the algae from the roof. I will warn you that this can damage the roof and take life off of the shingles, so it is always best to have an expert come out to your home and inspect the black spots to determine if it can safely be cleaned off, or if replacement options are recommended. 
Most shingle manufacturers have warranties for 10+ years against the growth of algae on the shingles.  Atlas makes a shingle that has a lifetime guarantee against the growth of blue-green algae based on the amount of copper granules they have in their shingle products.  For home owners who are concerned about the algae growth, replacing the roof with this product is a good idea to keep the roof beautiful up to the time for replacement.
Hope this advice helps and good luck with your roof!
David Silverstein, AROCON Roofing and Construction
Oct 10, 2014
black spots on the roof. can you tell me what is the cause of this? have lived in this house 12 years and have had no problems. what can you do to clean this?
Oct 18, 2014

This type of staining (algae as the other posters have said) will usually only happen on the North facing surface of the roof.  Same with condensation on your car glass.  Suprisingly, the North facing sky will actually remove heat from a substrate and thus make the roof surface colder.

Colder roof surface = condensing surface.  The moisture combined with the organic component will combine for a great growing surface (that the the rock dust organic component of the shingle).

It is not surprising that it is happeing more after you insulated the home.  By insulating (a good thing), you have reduced the heat sink between the roof and the conditioned space below and therfore made the roof colder in the process.  Colder roof...same as stated above. 

Plenty of roof washes out there that will handled most of this stuff and it does not mean the roof is cooked. 

Oct 10, 2014
black spots on the roof. can you tell me what is the cause of this? have lived in this house 12 years and have had no problems. what can you do to clean this?
Oct 13, 2014

Using the information you have provided and not visually inspecting the roof, the black spots on your roof are more than likely algae.  Most shingle manufacturers use copper or zinc coated granules to aid against the growth of algae.  As the rain washes over your shingles, particles of the copper are dispersed helping the prevention of algae growth.  Most manufacturers warranties will cover the first 10 years against streaking and staining, which helps to explain why you have not seen evidence of this issue before.  There are low pressure solutions available to clean your roof but they will not prevent the stains from returning.  The addition of copper or zinc strips under the first full course of shingles below the ridge cap could provide to be a longer lasting remedy.  I suggest that you contact a reputable local roofing contractor for a complete roof inspection before you make a decision on the remedy, as the algae can hold moisture and can prematurely age your shingles. ( Damon Ward Project manager At Allstate Exteriors llc.)

Oct 10, 2014
black spots on the roof. can you tell me what is the cause of this? have lived in this house 12 years and have had no problems. what can you do to clean this?
Oct 10, 2014

Hello Terry,

What kind of roof do you have? Is it an asphalt roof? The average lifespan of asphalt composite roofs is 10-15 years. Depending on how extreme the weather is in your area, some roofs made with temporary roofing materials may start to fail as soon as eight years.  

The most common cause of this type of dark spots is a variety of blue/green algae called a  Gloeocapsa Magna. Ths stains often evolve to a moss buildup, as the algae increases moisture. That is not only an appearance problem, as algae proliferation may shorten your roof life and increase energy costs. (You mentioned you recently added more insulation to your attic. Not only that was probably not the cause, but potentially, even the need for the extra insulation is already a sign of an underperforming roof.) 

There are products on the market to clean it, but keep in mind the algae also reduces the composite integrity, so removing it may still keep your roof exposed.

It would be advised to call a professional inspector to do a roof and attic inspection. It can identify any other related issues and give you a timeframe of how much longer can your roof can hold. 

Also refer to your warranty, keeping in mind each manufacturer have a different levels of protection. 

When it's time to re-roof, you may want to consider other lifelong roofing materials (such as metal).  

Feel free to contact us if you have any other question.

Regards,

Carlos (social@interlockroofing.com)

Oct 10, 2014
black spots on the roof. can you tell me what is the cause of this? have lived in this house 12 years and have had no problems. what can you do to clean this?
Oct 10, 2014

There isn't a lot of information, so I'll make some assumptions.  First the black "spots" are on the inside of the roof sheating, the black spots are assumed to be mold and you live in a cold climate?

If my assumptions are correct you probably have inadequate ventilation of the attic area causing moisture to accumulate, condense and probably freeze during cold weather (hence the spots being limited to north side where sun does not directly heat roof in winter) This water probably thaws in the spring and leaves enough moisture at the surface (water activity) for a long enough time with sufficient temperature to allow mold (probably Cladosporium) to grow.

This is probably either as a result of a moisture source, such as a bathroom vent or perhaps ambient moisture escaping the finished area at an attic access, can lights, etc.  I suspect when you added the insulation, the temperature of the attic space was lowered during heating season as less heat was lost to the attic from the finished space.

Probably need to verify that there are no sources adding moisture load to attic, then add or increase the size of the venting or add a humidistat activated exhaust fan to the attic space to correct the cause and then properly remediate the (apparent) mold.

If the spots are on the outside, the addition of insulation may still have changed the balance of the attic temperature, resulting in moisture staying on the roof longer than in the past as the roof is not heated and dried as quickly by the "lost" heat from the inside.  This may mean it is becomes a maintenance issue either by addition of a controlling agent in or on the roofing material or (annual) cleaning to remove the "spots" when they appear.

Oct 10, 2014
black spots on the roof. can you tell me what is the cause of this? have lived in this house 12 years and have had no problems. what can you do to clean this?

Over a period of time, shingles may develop dark brown or black streaks that are sometimes mistaken for soot, dirt, moss or tree droppings.  In actuality, this discoloration may be caused by algae growth. Although most
roofing systems are susceptible to algae discoloration, it is most readily visible on white or light-colored shingles.
Today many  of the newer asphalt shingles have an Algae Resistant granular system that guards against roof algae. The system uses copper roofing granules from 3M to prevent algae growth‚ protecting the roof and preserving the home’s be auty.  Here is a link to a good explanation....  http://roofpedia.com/algae-resistant-roof-shingles/ 

Oct 10, 2014
black spots on the roof. can you tell me what is the cause of this? have lived in this house 12 years and have had no problems. what can you do to clean this? spots are on the north side of the roof. starts up high on roof and come down about 3/4 of the way. the spots do not cover the complete roof. the only thing that has been done different this year is we added more insulation in the attic
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john barton asked:

Feb 18, 2014
Is there anything I can do from inside my attic to battle ice dams? I'll worry about preventing them next, for now I have them and want to speed up their melt.

Tim Brown JR of RGS Exteriors PRO answered:

Jul 10, 2014

The best way to fix and resolve ice dams is actualy proper isulation in the attic space. Next is proper ventilation. Both intake and exhaust. These are critcal but rarely done correct and very costly and hard to do rero. 

If the above are not done then a good qulity ice melting system is best. Either a commecial grade heat cable/heat tape or an ice melting system such as a heat panel.

Never use a continous watage cable as they are not safe or effecient. 

Only use a self regulating cable as they are safe and effecient. 

You will want the cable in the gutters and downspouts first, the next step is cable in the valleys and lastly weaved on the roof.

May 21, 2014
roof vents placed behind 4ft walls in finished attic dont do squat for ventilation. no place for soffit vents, siding is asbestos so gable vents too pricey.

Eric Consuegra answered:

Jul 9, 2014

Hey William, 

I would say your best bet is to shingle over the vents and edge the vents at eaves. This way you are able to allow for intake and continuous ridge vent for exhaust. Hope this helps!

Eric Consuegra

AROCON Roofing and Construction, LLC

May 21, 2014
roof vents placed behind 4ft walls in finished attic dont do squat for ventilation. no place for soffit vents, siding is asbestos so gable vents too pricey.
Jun 13, 2014

If the space behind the knee wall is clear from end to end and you install gable end vents at each end then that would keep the eaves from freezing and causing ice dams.Make sure the knee wall is well insulated. You want to keep the heat in the finished area and get the space behind the wall as cold as it is outside.What you need to do is create some convection in there. If you don't want to spend the money for this then you could try a high powered exhaust fan for one of the roof vents and try to get some air movement from that.

Feb 17, 2014
What's the best way to test out if my roof is leaking before it rains?
Jun 5, 2014

First have your roofer do a visual inspection for obvious areas where water could enter your home.  Then, do a simple water test.  Have one person look in the attic and one person in the home.  Have a roofer go on the roof with a running garden hose. Have the roofer start introducing water at the lowest parts of the roof and work up.  Have all 3 people on a cell phone conference line so that if water is seen coming into the attic or home the person on the roof can shut off the water. 

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