Anybody Know Anything About Roofs? - Page 3 - PeachParts Mercedes-Benz Forum

Brian Carlton · #31 11-03-2009, 08:47 AM

Quote:

Originally Posted by Zeus

Try carrying bundles of shingles (80lbs avg) across such a roof!

We'd literally aim to step on joists. Morning dew often helped define the joists, help you step on them. We all put our foot through roofs at one point or another...

Personally, I believe that the municipality is negligent in allowing such a roof. The entire purpose of the building department is to prevent such garbage.

1/2" OSB was bad enough...........the roof waves at you in 15 years.

Zeus · #32 11-03-2009, 09:06 AM

Quote:

Originally Posted by Brian Carlton

Personally, I believe that the municipality is negligent in allowing such a roof. The entire purpose of the building department is to prevent such garbage.

1/2" OSB was bad enough...........the roof waves at you in 15 years.

Fully agree. Mike Holmes would agree with you. Homeowner would agree with you.

I often wonder if it could be true that the builders have so much political and economic influence on those who make the code, that they simply lean with that weight until a compromise is reached - that being absolute minimum for safety and absolute best cost margin in terms of materials. It's only $2 more a sheet for 1/2" but multiply that by thousands...

kerry · #33 11-03-2009, 09:38 AM

Another advantage of metal roofs is that they are considerably lighter than shingles. The one I used is called a raised panel roof. Installs with neoprene washered screws thru the metal.

Mike D · #34 11-03-2009, 10:14 AM

There's another product you can check out.

It's called "Ondura". They have a website, ondura.com or some such stuff.

It's a asphalt composite (recycled I believe) sheeting much like a metal roof. I've been using it for my projects for the last 5 years or so. No leaks yet. Granted, my roofing requirements are different from you guys in the snow belt but check it out.

link · #35 11-03-2009, 10:25 AM

Quote:

Originally Posted by al76slc

We currently have a ridge vent running the length of the roof. Have these been improved on in the last 25 years, that we should think of replacing it?

One of my houses has ridge vents. I've read that they are fine BUT, it is imperative that the vents are in no way blocked. Accordingly, common failures for this kind of ventilation are due to 1) blocking the vents with insulation or plastic and 2) insufficient air flow due to not having large vent openings at the bottom or top.

I've read that houses with vaulted ceilings or which otherwise don’t have a lot of open space between the ceiling and the roof are not good candidates for ridge vents. I don’t know if this is true.

Hatterasguy · #36 11-03-2009, 10:55 AM

Quote:

Originally Posted by Brian Carlton

Personally, I believe that the municipality is negligent in allowing such a roof. The entire purpose of the building department is to prevent such garbage.

1/2" OSB was bad enough...........the roof waves at you in 15 years.

The building department sets whatever codes they want, the builders have no influence. At least in this city, I can't speak for others.

The quality of building departments varies widely, as does the quality and knowledge of inspectors.

I ain't naming names on a public forum but I know some cities are pretty corrupt. Also some rural ones are pretty liberal in the code enforcement area. You can spec whatever you want but if you don't enforce it, its worthless.

al76slc · #37 11-03-2009, 11:37 AM

Quote:

Originally Posted by link

I've read that houses with vaulted ceilings or which otherwise don’t have a lot of open space between the ceiling and the roof are not good candidates for ridge vents. I don’t know if this is true.

Interesting. My house fits that bill. Wonder if that had something to do with the sheathing buckling?

t walgamuth · #38 11-03-2009, 10:08 PM

Quote:

Originally Posted by Zeus

I ran a roofing/contracting business for a while (back when I was at university).

My thoughts -

Strip all the old shingles off, never lay new shingles over old. If you do:

they won't seal properly to the old shingles, creating air gaps and moisture zones
they will look unsightly as the roof's appearance will become uneven as the new shingles settle over the old, uneven surface
the extra weight can cause sags between joists, depending on how your roof was built

Furthermore, removing the old shingles will allow you to inspect your deck. This is critical and I would never do a roof without this step. Customers would always be amazed at the (often) extensive damage to the sheeting resulting from waiting too long to replace shingles. Often, by the time you have an actual leak inside the house, the roofing sheeting will have rotted in many areas, particularly along eaves, valleys, chimney and wall flashing areas (where the step flashing has been compromised).

Not sure what your building code is there, but here builders will often use thin OSB, just minimum code. If you want to strengthen your roof, don't layer over a sagging/aged layer. It adds extra weight and isn't really effective. Your joists may have a maximum weight allowance depending on span/beam type. Remove the old sheeting and re-sheet with 5/8 spruce. This is a big job though.

As shingles age, they begin to dry out, and will shrink in size and curl at the tips. This is when you should replace them, IMO. As they continue to dry out, the gravel surface of the shingle (which gives it protection and color) will also wear off and the tar paper portion of the shingle is exposed to the elements. It will wear very quickly at this point as the sun and UV break this layer down.

I would definitely remove all the old shingles, sweep the roof clean and then thoroughly inspect the roof deck. Nail (or screw) down any loose boards, resheet where necessary. I always used spruce plywood, not OSB.

Then apply an ice/water shield membrane to the first 3' of the eaves, the rake and along any valleys and around chimneys. Apply regular roofing tar paper to the rest of the roof, using a stapler (hammer stapler with 12mm staples for most roofs). Used painted (color match to shingles) and galvanized drip edge along eaves. Apply the drip edge first over bare wood, then cover with ice and water shield. Some people apply ice and water shield over the entire roof, but this is unnecessary IMO and a waste.

I would buy a premium shingle if you can, the 3D architectural ones are popular and look nice. Since they are often dual-layered shingles, they will last a long time.

Don't skimp on roof vents. The best vent last time I checked is a multi-ridged maxflo roof vent. Make sure all bathroom exhaust vents are properly connected to the appropriate roof vent, and not venting into the attic (which will destroy and rot the sheeting).

On the shingle warranty/lifetime numbers - they aren't very accurate.

Here in Ontario, a 20-yr shingle will last about 14 years. A 25 yr shingle maybe 18ish. If you are in an area with wide seasonal and temperature variations, the shingles will deteriorate faster.

Hope this helps.

P.S. If you are doing the roof yourself, rent a quality pneumatic roofing gun (I swear by Stanley Bostich) and wear a harness...it's a pain but so is landing on the ground after falling off (don't ask my how I know).

I agree with all of this but if the sheathing is sound I would not hesiatate to shingle over a layer if the stucture will take the extra weight.

t walgamuth · #39 11-03-2009, 10:11 PM

Quote:

Originally Posted by Zeus

Np, you are welcome!

I'm not a big fan of ridge vents, I find them problematic and prone to leaking. They have a large (long) surface area to seal, and this can be lifted by ice, etc. I would generally seal the area off (add new sheating and cap with shingles) and install a high-quality, high-flow roof vent instead. Mind you, we have nasty winters here with lots of snow and freeze/thaws...so your mileage may differ. They are probably fine in areas with little to no snow.

Skylights are always fun, especially if they were not installed correctly. The key is installation, and the flashing in particular. I like Velux skylights for this reason - excellent flashing kits. You need to install the flashing exactly as described.

If your skylights are leaking and old, you can consider replacements if your budget allows. Alternately, you may be able to either reuse and reinstall the original flashing, or purchase a new flashing kit for the existing skylight and then simply reinstall when doing the roof. If the skylight itself was in good condition, I would go this route (new flashing kit).

x2 on the velux. I have 16 on my home. I would not consider any other brand. In thirty years of practice as an Architect I have had between 2 and 300 installed on homes with excellent results in all cases.

t walgamuth · #40 11-03-2009, 10:12 PM

Quote:

Originally Posted by al76slc

Interesting. My house fits that bill. Wonder if that had something to do with the sheathing buckling?

If you have a cathedral ceiling all the way up a ridge vent is the only choice. I have used a lot of them but always use the shingle vent with the brillo pads (sortof) inside to keep blowing snow out.

Having no vent is not an option. it is against the code and for good reason.

MS Fowler · #41 11-03-2009, 10:15 PM

One of the problems I see with building codes is that the Code then defines the minimum acceptable materials. In a competitive marketplace, there is little incentive to build any better than the code requires--its actually more difficult to make quality a selling point. As a result builders use 3/8" OSB because its hard to convince a prospective buyer of the additional quality of the 1/2" or 5/8"--they all look the same at first.

kerry · #42 11-03-2009, 11:05 PM

Quote:

Originally Posted by t walgamuth

If you have a cathedral ceiling all the way up a ridge vent is the only choice. I have used a lot of them but always use the shingle vent with the brillo pads (sortof) inside to keep blowing snow out.

I used to manage a condo complex with ridge vents without the brillo padding. One time we had a blizzard with the wind blowing from one direction. An owner called me to complain of water dripping thru her ceiling so I climbed into the attic to discover a 4' drift built up under the ridge vent.

t walgamuth · #43 11-04-2009, 06:17 AM

Quote:

Originally Posted by kerry

I used to manage a condo complex with ridge vents without the brillo padding. One time we had a blizzard with the wind blowing from one direction. An owner called me to complain of water dripping thru her ceiling so I climbed into the attic to discover a 4' drift built up under the ridge vent.

I guess they would be fine where it does not snow....or rain.

rs899 · #44 11-04-2009, 06:45 AM

We don't have the snow or load issues down here in Florida, but I still had to come to grips with the issue of ripping off one layer of old shingles this summer when we put a new metal roof on. I really couldn't find much discussion or good information on it on the internet. The roofers all wanted to leave it alone- my best buddy was convinced that was the wrong idea. The underlying wood was sound so I left the shingles on and they installed the roof (Maxrib painted ivory) over 1x4 purlins.

So far, so good. It seems to save about 15-20% on my A/C bill over the dark shingle roof it replaced. Time will tell if it will last- I hope so because it cost the earth...

Rick

kerry · #45 11-04-2009, 09:16 AM

Quote:

Originally Posted by rs899

We don't have the snow or load issues down here in Florida, but I still had to come to grips with the issue of ripping off one layer of old shingles this summer when we put a new metal roof on. I really couldn't find much discussion or good information on it on the internet. The roofers all wanted to leave it alone- my best buddy was convinced that was the wrong idea. The underlying wood was sound so I left the shingles on and they installed the roof (Maxrib painted ivory) over 1x4 purlins.

So far, so good. It seems to save about 15-20% on my A/C bill over the dark shingle roof it replaced. Time will tell if it will last- I hope so because it cost the earth...

Rick

I would have done exactly the same. My roof (1890) had original skip sheathing. Code called for solid deck sheathing to be installed on top. I saw no reason why a roof which had lasted 100yrs already needed the additional layer so put my standing rib metal panel roof painted green on top of the skip sheathing. Doing fine 20 yrs later. My materials cost me $100 per square in 1990.