Porch roof

[czechsonofagun]

On the back of the house, there is a covered porch - the south kind with netting for windows - and the roof leaks. Period. It has only felt paper on top with seams tarped over but no matter what I do it leaks sooner or later again.

The problem is the slope, 12" over 10' span is way too low for the roofing. I measured it yesterday and checked tables and there is no way I can get the needed pitch without going to some extensive structural changes.

Shingles are 4:12 minimum pitch, MasterRib is 3:12 - it still means either going down 30" on the end of the porch or going up the roof - did I mention it is a one story house? - with the top of the porch roof.

Ideas, suggestions? I am thinking about doing a membrane now - like ice/water shield and shingles over it.

What do you think?

 

[Pipestone Kid]

You have several options. 1. rubber roof. 2. Conklin Products has a product called Rapid Roof. It is a nylon cloth that is stapled down and the a two coat process (first coat is a primer) of a liquid rubber. Great stuff! There are similar products out there, but I am not familiar with them and how well they hold up. I have used Rapid Roof and will swear by it. HTH

 

[radioman]

I am sorry- I am not sure of what material you are referring to exactly for the roof?

My rental house has a same low sloping roof as yours and I use the half lap mineral sheeting roll. I use the roll roofing adhesive on top half and glue them together. Havent had a leak yet, but I have to redo it every 10 years if I use the 15 lb paper due to sun and snow wearing away. You stated is on south side so a 30 lbs is needed.

 

[smstonypoint]

You may want to check out other metal roofing products. I think others may have lower limits on their recommended roof pitches. I have no direct experience with rubber roofing products, but I suspect that they involve more maintenance than metal roofs. Another advantage of a metal roof -- the sound of rain.

Steve

 

[czechsonofagun]

Thank you guys!

The sound of rain for metal roof is definitely a consideration

The problem with metal roof and low pitch is the standing seam that has to be done on the roof, I don't have experience with it and can't afford to pay for the work.

 

[brin]

Thank you guys!

The sound of rain for metal roof is definitely a consideration

The problem with metal roof and low pitch is the standing seam that has to be done on the roof, I don't have experience with it and can't afford to pay for the work.

I agree with the previous poster...Look into Asphalt roll roofing...easy to put down and you use an adhesive between runs and you should not have any leaks...inexpensive and lasts a good long time.

 

[rtimgray]

We had a similar situation on a rental house. The only difference was at one point the porch was converted into a couple of bedrooms, so the leaks were a bit more consequential. For many years, we used the roll-roofing product. We usually only got about 5-7 years out of it before it started leaking again, but it wasn't a big deal to replace (which is one advantage of a low-slope roof - easy to stand and work on). We eventually did a structural remodel to the house and raised the pitch of the roof were able to use normal shingles.

If it were me, for a porch roof, I would go with the roll-roofing.

 

[TnWV]

I had the same problem with my porch roof. I shingled it and it leaked everywhere due to not enough pitch. Roll roofing was my solution. The stuff is cheap and very easy to install in no time. I nailed the top, overlapped the next run about 4 inches, and used a beam of asphalt caulk to lock down the overlap. I tucked the final row under the the layer of shingles where the porch roof meets the house roof. This was over 5 years ago and no leaks since. It may not look the best from above,but no one ever sees it anyway. If you don't want the expense of metal, roll roofing, IMHO, may be your best option.

 

[MapleLeafFarmer]

google
- flat roof options
- flat roofing membrane


and you have lots of options available to you. A rubberized membrane is the way I would go give what you say above.

no need to change the slope just use the right products and you should be good to go....

 

[smstonypoint]

Thank you guys!

The sound of rain for metal roof is definitely a consideration

The problem with metal roof and low pitch is the standing seam that has to be done on the roof, I don't have experience with it and can't afford to pay for the work.

Prokop,

I have no experience with this metal product -- Benton Metal Depot - Investment Grade Roofing, Residential Metal Roof, Metal Roofing Contractor, Metal Roofs, Aluminum Roofing, Steel Roofing, Aluminum Roof, but the site claims it can be used with a minimum 1:12 pitch even though it is not a standing seam product. I'm not trying to argue that you should go for a metal roof, just trying to give you an alternative that might be worth exploring.

Steve

 

[ustmd]

Prokop,

I have no experience with this metal product -- Benton Metal Depot - Investment Grade Roofing, Residential Metal Roof, Metal Roofing Contractor, Metal Roofs, Aluminum Roofing, Steel Roofing, Aluminum Roof, but the site claims it can be used with a minimum 1:12 pitch even though it is not a standing seam product. I'm not trying to argue that you should go for a metal roof, just trying to give you an alternative that might be worth exploring.

Steve

We have standing seam metal roofing on our barn and workshop--can't remember the exact pitch, but between 1:12 and 2:12. The barn has been up since 1999 with no leaks, workshop 2010, no leaks. Of course, I am in Central Texas with only rain to worry about.

 

[czechsonofagun]

Thank you, Steve,

That metal roofing looks just like MasterRib, but MR has minimum pitch 3:12:

MasterRibｮ Metal Roofing Panels - Install Metal Roof Panels - Union Corrugating

I wonder if doing a membrane and shingles on top of it will make it last longer, since shingles will protect it from the sun?

Thank you all for suggestions, TBN helpful as always :thumbsup:

 

[tcreeley]

In snow country I found that roll roofing did not hold up in low pitch situations well - even with adhesive overlap. Ice dams formed and found ways between the layers. I think I would putdown a layer of membrane, 2x4 cross hatch and metal roofing on that. If the roof is vented- that will cut the ice dams. Water will just run down the ribbed panels that are screwed down with rubber washered screws. The standing seam stuff is nice- more expensive. I bought from this company Metal Sales Manufacturing - Metal Roofing, Siding and Wall Panels through Home depot pro panels.
It is not all that hard to do- just need to think it through. I never hire anything out.
Electric metal snips make the difference and a good electric drill to drive screws- (Dewalt is good). Good luck.


Up here, no one uses membrane by itself - lasts only a year or so then leaks. They use membrane instead of the 15lb felt (tar paper) they used to use. Membrane is a catchall if the rain gets through the shingles, and is self sealing around the nails driven through it.

 

[czechsonofagun]

I remember seing overlaping panels at Home Depot, is that what you used? I put a roof on kids tree house using those, they are nice and easy to work with.

 

[orezok]

If there are any metal building companies near you, check with them. Many metal buildings are 1:12 pitch using a type of corrigated panel with butyl sealant between to insure waterproof. Easy to place, just screw down with neoprene washers.

They can ever provide panels to your exact length requirements up to about 30' so not horizontal joints.

 

[tcreeley]

The panels at Home Depot are similar but in my area made by a different company. The panels I got were special order- Pro-Panel and Classic Rib. I gave them the measurements and they cut to length. (You need to work out every piece you will need, choose paint color, and order altogether.)
check this site:
Metal Sales

I searched minimum pitch on their site and got specs for each panel type. The search is at the top right corner of their page - "minimum pitch":
Metal Sales Mfg. - Residential Metal Roofing, Siding and Wall Panels
Good luck.

 

[czechsonofagun]

Thank you!

 

[EddieWalker]

Home Depot and Lowes sell a thinner, lesser quality metal for roofing then you will find at most metal building suppliers. 1:12 pitch for metal roofs is pretty standard where it doesn't snow. I've done it quite a few times and have had great results. I buy premium materials and refuse to use anything else.

I've had good and poor results with rubber roofs. They are as good as the prep work that goes into them and the quality of material that you buy. Stip whatever you have down to the wood and make sure it's solid. Be sure that the decking isn't sagging or has any bounce to it. Rubber has some give, but it hard to seal around the edges. Asphalt roll on is easier to install, but will fail quicker. Especially if there is any movement!!!

Rember that with a shallow roof, the edge tends to hold water and if you don't have a good drip edge, water will want to hold onto the edge and come back under the roof and behind the fascia. This is VERY COMMON, and a big reason that people call me out. The fascia and soffits are rotting out and they don't understand why. In every case, it's because water is coming back under the roof.

Eddie

 

[czechsonofagun]

Thank you, Eddie.

I always buy metal roofing through the local farm coop, they place the order in the roofing factory, the quality is proven on barns over and over again.

 

[LeadPoison]

Option 1:

Rip it off.
Inspect and clean decking.
Install Tamko Tile and Metal Underlayment.
Install double lock standing seam panels with butyl caulk tape. If you can't get someone to make and install these, find the tallest standing seam you can find. Use butyl caulk tape too.

Option 2:
Copper flat lock roof. Super expensive and I doubt you can find someone who can install it correctly. But if you have the $$$ it will last 100 years. We have installed these on many churches around the country.

Option 3:
EPDM (Rubber)
Fairly easy to do yourself and lasts maybe 10-12 years.

I'd go for Option 1. Preferably something with a Kynar finish.

Hope this helps. Let me me know if you need any info or help.