New roof estimate

[Squiner]

How was it flashed originally? Is it still there? Can it be reused and just reinforced with his step flashing and caulk? This is a major weak point in a lot of roofs. I don't think I have ever taken one apart and not found rot around the chimneys. I don't think I would rely on caulk to seal the step flashing to the masonry.

I can't tell exactly how it was originally flashed since it is all slathered up with caulk. The step flashing only gets nailed down to the roof. The flashing that covers the step flashing gets sunk into the mortar joint. I've read that it should be sunk into new mortar on one website and into caulk on other websites. I think either are fine I guess.

The contractor said the flashing will be all new. And yes, my rafters near the chimney have some rot which I need to reinforce.

 

[peakbagger]

Most of the shingled commercial construction in my area has the roof decking covered entirely with EPDM (Grace stormshield). I think its too fold, the likelyhood of call backs and roof leaks is minimal and they dont have to worry if it rains once the EPDM is laid down. The EPDM seems to last forever as long as its got a UV barrier on top of it, like shingles. I would expect the shingles would get visually worn out long before the roof leaks. EPDM for the first six feet is standard for ice dams. They can and will still form if the roof ventilation is not right, but generally it keeps the water from getting back into the house as it does seal the roof nails quite well. On houses with a lot of gables and roof pitches, the standard seem to be fill in the valleys completely.

A lot of the standing seam metal roofing contractors in the area also install EPDM under the metal as, its almost impossible to trace a standing seam leak to its source making call backs very expensive.

 

[Hogwildz]

How was it flashed originally? Is it still there? Can it be reused and just reinforced with his step flashing and caulk? This is a major weak point in a lot of roofs. I don't think I have ever taken one apart and not found rot around the chimneys. I don't think I would rely on caulk to seal the step flashing to the masonry.

I can't tell exactly how it was originally flashed since it is all slathered up with caulk. The step flashing only gets nailed down to the roof. The flashing that covers the step flashing gets sunk into the mortar joint. I've read that it should be sunk into new mortar on one website and into caulk on other websites. I think either are fine I guess.

The contractor said the flashing will be all new. And yes, my rafters near the chimney have some rot which I need to reinforce.

He could reuse the old counter flashing around the chimney, if he is going to put new on, the old stuff should be removed. Either way, we always used a good caulk, I'm preferential to urethane caulk, the same caulk used in masonry wall expansion joints. Grouting at this point (not during the building of the chimney) has a chance to fail and crack & fall out. A good caulk will do a great job, but only if done right in the first place.
Either way he needs to clean that old caulk out, which is not easy if it was done right. Often times we would cut a new reglet joint a couple inches above the old joint and install a new counter flashing in the new joint & caulk tight.
If we took the old counter flashing out, I would also caulk the tops of the new step flashing as a back up protection in the case the counter should leak for any reason. Not really needed if the counter is sealed good, but extra protection never hurts.

 

[[email protected]]

I've seen allot of good tips on here. Caulking the top of the flashing into the mortar joint will work perfectly. In out area anyway that is very much a standard practice.

I would make one caution with the Ice and Water Shield. While it is code in out area to use in on the bottom of the eve, and everyone does it. Allot of people like to try and cover the entire roof with Grace thinking it is better, and it can be. It will stop water from getting to the plywood in the event of shingle blow-off or ice dame etc. BUT - you have to make sure your roof is VENTILATED properly first. Otherwise you can create condensation issue on the bottom of the plywood. I personally have been in attic where this happened. It almost looks like the roof is leaking. So, Ice and Water is an excellent investment. And will give you extra protection, but if you don't have adequate ventilation, covering the entire roof deck with it, can cause big issues.

As far as cost, we sell felt for about $4.00 per sq. Grace is $55.00 PER SQ. IKO Armour Guard Ice and Water is like $30.00

Hope all this informtion from the thread help you tons and good luck with your project. Sounds like your going to have a good roof job done for a fair price, and that is all you can ever hope for.

 

[Squiner]

I've seen allot of good tips on here. Caulking the top of the flashing into the mortar joint will work perfectly. In out area anyway that is very much a standard practice.

I would make one caution with the Ice and Water Shield. While it is code in out area to use in on the bottom of the eve, and everyone does it. Allot of people like to try and cover the entire roof with Grace thinking it is better, and it can be. It will stop water from getting to the plywood in the event of shingle blow-off or ice dame etc. BUT - you have to make sure your roof is VENTILATED properly first. Otherwise you can create condensation issue on the bottom of the plywood. I personally have been in attic where this happened. It almost looks like the roof is leaking. So, Ice and Water is an excellent investment. And will give you extra protection, but if you don't have adequate ventilation, covering the entire roof deck with it, can cause big issues.

As far as cost, we sell felt for about $4.00 per sq. Grace is $55.00 PER SQ. IKO Armour Guard Ice and Water is like $30.00

Hope all this informtion from the thread help you tons and good luck with your project. Sounds like your going to have a good roof job done for a fair price, and that is all you can ever hope for.

Thanks for the advice.

To follow up with what you have said, I don't have very good ventilation. My soffit vents have a 1" hole cut into the board between the rafters. I'm not sure, but I would guess that this isn't adequate. Do you agree? I guess I will have to take a hole saw and cut bigger openings. What is an appropriate sq-in opening to provide adequate ventilation from eave to ridge vent?

Also, just to get a better understanding; does the ice and water shield exacerbate the ventilation/moisture problem over basic felt because it has superior moisture transmission resistance?

 

[[email protected]]

According to the FHA (Federal Housing Administration (US) for every 300 square feet of attic floor area you should have, at minimum one square foot ventilation. Here is good link which explains the calculation's in nice easy terms. BTW I have a fairly large flat roof. Flat roofs are particularly difficult to get to ventilate properly. It may be cheaper to invest in what I like to call whrily bird (turbine type), Your roofer can install them and flash them for you.

http://www.renovation-headquarters.com/attic-ventilation-calculation.htm

Felt paper is somewhat permiable. so it will let some moisture through. So this will cause less of a problem.

If you find that you don't have adequate ventilation. You might consider spending some of the budget on updating the ventilation rather than ice & water. I say this because it will prolong the life of your replacement shingles, it will help with cooling costs in the summer, and it will also help to minimize Ice Damn to some extent. note- Ice and water does nothing to stop ice damns. But it does protect your roof underlayment and the inside of your home if it should occur. Either way, I expect that roof damns aren't an issue in MD.

 

[[email protected]]

To follow up with what you have said, I don't have very good ventilation. My soffit vents have a 1" hole cut into the board between the rafters. I'm not sure, but I would guess that this isn't adequate. Do you agree? I guess I will have to take a hole saw and cut bigger openings. What is an appropriate sq-in opening to provide adequate ventilation from eave to ridge vent?

Also, just to get a better understanding; does the ice and water shield exacerbate the ventilation/moisture problem over basic felt because it has superior moisture transmission resistance?

Yes you are understanding the ice and water issue perfectly.

As far as the ventilation requirements I would need the actual dimensions of your roof / house. But that doesn't sound adequate.

BTW - That was not meant to scare you. This might not be an issue for you at all. It really depends on your life style and how much "water vapor you cause. ie. cooking, showers, humidifiers, dishwashing etc.

 

[Squiner]

Yes you are understanding the ice and water issue perfectly.

As far as the ventilation requirements I would need the actual dimensions of your roof / house. But that doesn't sound adequate.

BTW - That was not meant to scare you. This might not be an issue for you at all. It really depends on your life style and how much "water vapor you cause. ie. cooking, showers, humidifiers, dishwashing etc.

I think I can figure out the calculations. The only difference I have is that my house is one story with cathedral ceilings throughout. So I think I am limited to drilling holes. Another issue with my ventilation is that I don't have the baffles in the cathedral ceiling. Fortunately, the 1950's insulation (thin cellulose between felt) is so poor that it doesn't even touch the sheathing.

Another option that I have been thinking about is removing the drywall and insulation in the ceiling and replacing it with expanding foam. I have read conflicting information about not having to have ventilation at all with the foam. That way I could take advantage of the full volume of space for insulation.

Do you have any experience with this?

I really appreciate you taking the time to answer my questions, sorry for so many!

 

[[email protected]]

No problem at all.

I know a little about spray foam but not enough that I would want to recommend the application. I know it's a good product and getting better.

I know there are 2 types closed cell and open cell. I believe closed cell is the type your referring to. It has a really low perm factor which makes it act as both moisture barrier and insulation.

I'm under the impression that most people use open cell due to the cost. I have a local contractor who uses closed cell, but only uses an inch or so, then adds fiberglass on top on that. (I think he said that closed cell was like $1.00 per board foot applied. ugghh)

After reading this reply it sounds like I'm trying to say I know something about the stuff. But not really, I guess I'm regurgitating stuff I've been told and overheard.

 

[Squiner]

No problem at all.

I know a little about spray foam but not enough that I would want to recommend the application. I know it's a good product and getting better.

I know there are 2 types closed cell and open cell. I believe closed cell is the type your referring to. It has a really low perm factor which makes it act as both moisture barrier and insulation.

I'm under the impression that most people use open cell due to the cost. I have a local contractor who uses closed cell, but only uses an inch or so, then adds fiberglass on top on that. (I think he said that closed cell was like $1.00 per board foot applied. ugghh)

After reading this reply it sounds like I'm trying to say I know something about the stuff. But not really, I guess I'm regurgitating stuff I've been told and overheard.

It's enough for me to get started researching, didn't know about open or closed cell. thanks

 

[Squiner]

In case any one else has this same issue with cathedral ceilings and venting, I found a website with a great article.

http://www.buildingscience.com/

Go to the information link and type in "Unvented Roof Assemblies for All Climates". Talks about Closed-Cell Spray Polyurethane Foam (ccSPF) and it's correct application.

It's amazing that with 2x6 rafters I can have an R-value of about 34 with the ccSPF. I really need to look into this more.

 

[[email protected]]

Nice link. I just learned a bunch.

Makes me want to fix my attic.