# Shed Style or Truss?



## my5sons (Oct 29, 2008)

I NEED IDEAS!!!!! I am requesting help on which roof style would be easiest for me to build/use on the porch which I have attached. It is a 31.5 ft x 8 ft porch. I used double 2x10 beams for the front and side and will use the top plate of the wall on the garage side. I notched the top of the double beams and laid them back into the wall with double 2x4's supporting them underneath (inside the walls). I know I'm waiting until the last minute here (rest of the porch is practically completed.

I have a 4/12 pitch on my current roof, which really sucks because if I build the shed style roof, the most I can get out of it is 3/12. I plan on using architectural shingles. 

I have quotes for Trusses from a truss manuf co. for approx $500 for gabel style 31.5ft trusses spanning the length of my porch. The problem is I can't visualize how I would tie 2 gables together. Not to mention I will need to join the valley with an acceptable method (again probably 3/12 pitch)

For the shed style roof, I guess I need to know if 2x6 will be ok for the bottom chord and where the supports would need to go? 

FYI, I don't need plans in my county to get the permits. It just needs to be built to code (2003 Residential Building Code)


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## my5sons (Oct 29, 2008)

anyone?


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## drtbk4ever (Dec 29, 2008)

I don't have any input, just a question. 

Are you planning on running the trusses the 31.5 foot direction or the 8 foot direction? Either way I see some added work to tie the porch roof into the existing roof on the house and garage.

If the 31.5 foot direction, you will need to have trusses up the roof of the house. Each one getting progressively shorter until you reach the peak of the house. Then you will have a valley on each side and a nightmare along the garage.

If you are going the 8 foot direction, are you thinking you will carry them part way up the roof?

Hopefully we will get the experts opinions here shortly.


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## drtbk4ever (Dec 29, 2008)

Have you thought of making the porch into a pergola?


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## my5sons (Oct 29, 2008)

Thanks Bill, no pergola, I want covered porch.

As for the gable roof, it will span the full 31.5 feet. I am going 16 in on center with the trusses and will have to continue the gable up the existing roof by tieing in a new ridge beam and stick framing off the ridge board to finish the gable. I would need to create a cricket to join the 2 gables, but am unsure how I would do this with the way the garage reverse gable and new gable will meet forming a new valley.

If I do the shed roof, I will place 2x6's perpendicular to the existing roof. (running the 8 foot length)


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## drtbk4ever (Dec 29, 2008)

OK, I got it.

I think having that clarified will get some input from the experts.


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## my5sons (Oct 29, 2008)

I have attached the rough quote with drawing for the gable trusses. I forgot to tell him that I don't need any overhang on the garage side and I only need 31.5 feet trusses with 18" overhang on 1 side, but before I order them, I will tell him.


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## vsheetz (Sep 28, 2008)

I faced something similar with a room addition I did several years ago. The right way to do it is to tie the new roof into the long ridge that is parallel to the porch. So you have new rafters from the ridge to the front edge of teh porch. Carry this all the way down to the ridge line that is perpendicular to the porch. This would be best stick built rather than with trusses. This is major surgury to the house.

An alternative that would be simpler is to make the roof U shaped rather than L shaped when done. Leaving a open space over the doorway area. This eliminates much of the extensive surgery. Use trusses as you have been quoted over the porch, and stick build the tie to the existing roof.

This alternative method is what I did...

Or go with the shed roof...


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## oldfrt (Oct 18, 2007)

I'd keep it simple,going with the shed roof as sheetv recomended.
Probably could have lowered that beam a little to gain pitch.
Of course this would put the end of the overhang below the garage eave and your valley would dump on your stairs so a gutter would be needed.
At the house wall frame up off top plate to support rafters, ledger againts house wall,2x6 ceiling joists from house to beam,leaving some of the beam exposed.

Too bad I didn't catch your post earlier,there is a way the porch floor could have been dropped a step to gain pitch also.


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## my5sons (Oct 29, 2008)

vsheetz said:


> An alternative that would be simpler is to make the roof U shaped rather than L shaped when done. Leaving a open space over the doorway area. This eliminates much of the extensive surgery. Use trusses as you have been quoted over the porch, and stick build the tie to the existing roof.
> 
> This alternative method is what I did...
> 
> Or go with the shed roof...


I know exactly what you are talking about. That was my original plan, (leaving a space in the doorway) but I didn't like the way I was going to have 2 ceilings (1 above the stairs and then a double 2x10 beam before another opening for the main porch). I can easily move back to this setup, if I just add another double 2x10 beam on the second post (from the garage) This will give me a gable span of about 25.5 feet and then I put a shed roof to join them. I believe I used the term 'cricket', but I guess that is the wrong term.


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## my5sons (Oct 29, 2008)

oldfrt said:


> Too bad I didn't catch your post earlier,there is a way the porch floor could have been dropped a step to gain pitch also.


Thanks, I did drop the porch down 3 inches, which put me at the max. I built the porch to the American Forest and Paper Association Wood Deck Construction Guide. I didn't cut corners anywhere!

http://www.awc.org/Publications/DCA/DCA6/DCA6.pdf

As for dropping much further...I don't like that most of the houses where I have seen porch additions, actually look like porch additions. What I mean is that I wanted mine to look like it came with the house. My final ceiling height is 8'4". I didn't want it to feel like a cramped porch and I like that you can see my entire window. I plan on replacing those old windows with updated windows. I wanted an open porch.


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## my5sons (Oct 29, 2008)

Why can't I do something similar to this?


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## oldfrt (Oct 18, 2007)

I know what you mean about the windows.
From the angle of the photo,it looked like there was some room to lower the beam.
If your replacing the windows,they could always be lowered easier than raised,but then there's the patching,sheetrock and siding.

I haven't read your other threads but if you could draw everything to scale,it will give you an idea of how it will look.


Your other idea:
I know exactly what you are talking about. That was my original plan, (leaving a space in the doorway) but I didn't like the way I was going to have 2 ceilings (1 above the stairs and then a double 2x10 beam before another opening for the main porch). I can easily move back to this setup, if I just add another double 2x10 beam on the second post (from the garage) This will give me a gable span of about 25.5 feet and then I put a shed roof to join them. I believe I used the term 'cricket', but I guess that is the wrong term. 

Could also work without the two ceilings affect.
You could have the trusses designed to fit into a girder beam.
This could be put on your existing top plate and the end of the trusses would sit in hangers flush with the bottom of the beam.
I like this shorter gable idea because it cuts back the size of the new front gable,making it close to the size of the existing gables.
With a 32' gable I'd be afraid of overpowering the front of the house.


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## oldfrt (Oct 18, 2007)

my5sons said:


> Why can't I do something similar to this?


 
I don't know about that,it seems you would be way above your existing house ridge with this approach.

Scale it draw it out,you'll see what I mean.
Too big IMHO.


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## my5sons (Oct 29, 2008)

oldfrt said:


> Could also work without the two ceilings affect.
> You could have the trusses designed to fit into a girder beam.
> This could be put on your existing top plate and the end of the trusses would sit in hangers flush with the bottom of the beam.
> I like this shorter gable idea because it cuts back the size of the new front gable,making it close to the size of the existing gables.
> With a 32' gable I'd be afraid of overpowering the front of the house.


Wow! Thanks, I would have never known that to be possible. That is a great idea. Thank you, thank you....

Man, I knew there was a reason to post for ideas on this forum!


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## my5sons (Oct 29, 2008)

I just realized something. If I put a beam on the top plate of my existing wall to tie the gable trusses into, that beam will be way above the double 2x10. How on earth would I tie the 2 gables together? hmmm, maybe I'm not understanding this????

Are you saying I could put the beam on the garage side and have the bottom chord of the trusses extend to the top plate of the garage wall?


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## oldfrt (Oct 18, 2007)

my5sons said:


> I just realized something. If I put a beam on the top plate of my existing wall to tie the gable trusses into, that beam will be way above the double 2x10. How on earth would I tie the 2 gables together? hmmm, maybe I'm not understanding this????
> 
> Are you saying I could put the beam on the garage side and have the bottom chord of the trusses extend to the top plate of the garage wall?


 
I was referring to putting a beam above the first post from the existing beam to the house and having the trusses butt against it at ceiling height.The left side would extend past the beam you have there with an overhang.Then build the shed style roof over the remaining open spot above the door and form a valley into the garage roof.


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## Gary in WA (Mar 11, 2009)

Look for Willie's post, click on his name, let him look at it, he might draw you both views. His sketch-up's are great! Your trusses say 32', may want to change that, even for a quote. (That's how mistakes happen to start out). And 24" on center rather than 16", quite unnecessary. Be safe, G


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## my5sons (Oct 29, 2008)

I have truss manuf working on it now, and this is what he says when asked about building mono-trusses. FYI, He talks about the 48' length, and he's right, my house is only approx 33 feet deep (I'll have to measure again to be sure, but I'm at work right now.)

8' - 0 monos at 3/12 pitch will not work for this house. If I assume that the heel heights match on the monos and the existing house, then the monos will be 24" higher at the heel of the house than the house itself. Since the main house is a 4/12 pitch and the monos are a 3/12 pitch that leaves a 1/12 pitch difference between them. That means 
the main house would have to be 48' - 0 deep in order for the monos to intersect the main roof. I can't tell from the pictures but I don't believe that is the case. As a result, the 3/12 mono roof plane would overshoot the main house ridge. Please look at the pitches involved. To better help I attached a form to fill out on your existing truss and send back to me. Let me know.


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## my5sons (Oct 29, 2008)

Here are my measurements: according to my calculations, the garage roof is actually a 4 1/4 pitch, and the Main House is 4 3/16 pitch. I guess I could be a little off, I'm measuring, trying to push my tape measure through blown in insulation in the attic spaces. Otherwise, you would think with Manufactured trusses, they would be dead on with 4/12.

A. Main House:

1. Overall Truss Height: 67 inches to 67 1/4 inches depending on which Truss I measure (there was a roof fire from what I was told prior to us purchasing this house, so it is re-built with manuf 2x4 trusses. I wish they would have gone with a 5/12 pitch or something better than this 4/12 crap.


2. Overall Heel Height: 3-3/4 inches

3. Overall Span: 32 ft.

4. Overhang: 16 in.

5. Ridge to Outside Face of Bearing: 16 ft.


B. Garage:

1. Overall Truss Height: 44.5 inches (manuf 2x4 trusses again)

2. Overall Heel Height: 3-3/4 inches

3. Overall Span: 21 ft.

4. Overhang: 16 in.

5. Ridge to Outside Face of Bearing: 10 ft. 6 in.


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## Willie T (Jan 29, 2009)

A few views................. Only two, the shed and the large gable flowing into the garage roofline seem workable.


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## my5sons (Oct 29, 2008)

Willie, that definitely helps me understand this better. I agree, and will probably end up with the shed style roof. Any recommendations on a DIY modified roof to help with the 2.25/12 pitch?

I received the quote for mono trusses. This is what he says.



> The best we could get on the pitch is 2.25/12. Anything higher than that
> will put you over the garage ridge ( see layout ). You will need to
> attach a ledger to the exterior wall to provide support at the high end
> of the monos.


So my questions:

1. 2.25/12 pitch. Can I still use Architectural Shingles? What about a modified roof? What system is best?

2. I looked at the mono-truss drawings, and see that the top chord doesn't extend to my existing roof. I'm assuming I need to add this, will a 2x6 work? Do I need any other legs when I add this top chord attachment to my 4/12 roof?

3. Why do I need to install a ledger for support on my outside wall? Can't I just cut the overhang from my existing roof and use the top plate of my outside wall? If I have to install a Ledger, what size is needed? 2x6, 2x8 or 2x10?


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## Willie T (Jan 29, 2009)

A few rough views of the shed type. No details, you can work that out.


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## oldfrt (Oct 18, 2007)

First off,
Excuse me Wille for butchering your drawing.

I think the OP had mentioned this possibility at one point.
Shorten front gable to first post.
Head off from first post to house for truss.
Build (black area) cricket/shed roof between new and existing garage roof.
Definately not to scale,but the smaller front gable may fit better and alleviate the two valleys dumping into one another.
You nay be able to get that 41/2 pitch to work here.


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## my5sons (Oct 29, 2008)

Thanks again Willie, I would rather have a gable, but the shed style is looking better. Thank you VERY much for the drawing samples. Easier at least to see what it will look like. 

Any suggestions on the modified bitumen roof or something that will help me with a 2.25/12 pitch?


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## my5sons (Oct 29, 2008)

oldfrt said:


> First off,
> Excuse me Wille for butchering your drawing.
> 
> I think the OP had mentioned this possibility at one point.
> ...


Thanks oldfrt. I do like the drawing you butchered!  The problem is, I will have to add another beam coming off that post, and there are 2x4's for my existing outside wall that are in the way. I will need to cut these to notch the beam. I guess I could hang them off the face of the 2x4's, but the other issue is I won't have a consistent ceiling height. hmmmm, decisions, decisions.

I think I've stated this earlier, but I could easily add a "fake gable" like a dormer later if I decide on something to make it look more appealing.


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## Willie T (Jan 29, 2009)

my5sons said:


> Thanks again Willie, I would rather have a gable, but the shed style is looking better. Thank you VERY much for the drawing samples. Easier at least to see what it will look like.
> 
> *Any suggestions on the modified bitumen roof or something that will help me with a 2.25/12 pitch*?


Nope. I live in a low pitch house, and I've just given up on ever using shingles.


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## my5sons (Oct 29, 2008)

Believe it or not, I'm still working this roof. I need to know the easiest way to calculate and make the new valley. Do I use a level from the closest truss to the garage and mark a line? Do I just use a valley board nailed to the side of my garage gable? If so, what size 2x6 2x8?. I have my trusses in place and I'm trying to figure out how to continue from the garage wall and into the existing valley. It looks like my Rafter connecting from the peak to this rafter will be about 18 feet long. I don't even know at this point if that is possible. 

Any recommendations or help?


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## Gary in WA (Mar 11, 2009)

Start a reading a few pages back: http://books.google.com/books?id=vT...rr=3#v=onepage&q=valley board framing&f=false
Be safe, Gary


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## my5sons (Oct 29, 2008)

Thanks GBR, but those pages, and everything I have searched online are really talking about valley framing for gable roofs. I'm concerned with a creating a new pitch over an existing pitch. My roof is a 4/12 pitch, and I am just tryng to frame a new pitch over top of it and extending it out to cover a porch. Obviously, this creates a new valley...

Here is the drawing of the roof I am putting up over my porch (2.25/12 pitch): (yes, I know the pitch is low slope, but the project is nearly done. I live in South Carolina - no snow loads etc.)










I need to frame the new valley so that I can put sheathing on it before the next rain. I'm kind of lost. I know I could use a valley board and then bevel it to the angle that the sheathing can attach to it, but what do I do with the space in between the last truss (next to the garage wall, and the valley? I need rafters or something to fill the space right? Approx 16 feet. I don't have a knee wall to support rafters that long. What size rafters do I need 2x10? 2x8? It sounds easy, but I want to make sure I am doing this right. I am re-shingling with approx. $3,000 in shingles and materials. Don't want to see my roof sag in the vaelly in 2 years or less!


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## Gary in WA (Mar 11, 2009)

Page 229--- diagram 15-10: http://books.google.com/books?id=KK...oof valley on intersecting gable roof&f=false Use ? or 3-2x6's may be wide enough on the garage roof to give* full support* to the valley jack rafters. These spans/wood will work, look for roof spans and the wood species: http://books.google.com/books?id=HM..._brr=3#v=onepage&q=rafter span tables&f=false 

Be safe, Gary


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## my5sons (Oct 29, 2008)

Thanks again GBR, but I don't have valley jack rafters, those are used on the garage wall gable when they built it, but I am not doing anything to the garage reverse gable. The diagram you pointed me to has a blind valley board that lays flat on the roof. My valley board will need to follow the profile of the valley of the 2.25/12 pitch and will need to be beveled on one side to be able to support the new sheathing. I have used mono trusses sitting on the top plate of my wall for my 2.25/12 pitch, then attached 2x6 to the side of the mono trusses and then to a 2x6 ledger laying flat near the peak. I notched a "key" into the 2x6 rafters and nailed them near the new shed ridge.

I'm at the point now, where my mono-truss sitting next to the garage wall needs to continue on to the new valley. Anyone know how I can do this?


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## my5sons (Oct 29, 2008)

lol, I think I got it GBR. I was just looking at the picture wrong. The pic in 15-10 that you pointed to IS actually what I am doing, I just have to look at it a different way, it is essentially a gable, and my ridge is just flat agains the roof...I'm just changing the pitch right? So my plans to do it this way were correct, I just need to make sure I am covering the span correctly.


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## my5sons (Oct 29, 2008)

Wow, those tables are confusing as heck.

I used this with 16 feet span, Deflection L/360 and 20psf live load: Says I should use a 2x10

http://www.awc.org/calculators/span/reversecalc/reversecalc.asp?feet=16&inches=0&species=Southern+Pine&member=Rafter+%28Roof+Live-Load%29&deflectionlimit=L%2F360&spacing=24&liveload=20&snowload=-1&deadload=10&wet=No&incised=No&submit=Calculate+Span+Options

So, I'm wondering if I did this correct? My truss designs say:

*DEFL*
*Vert(LL) 360*
*Vert (TL) 240*
*Horz (TL) n/a*

What is the correct Deflection I should use?

*TCLL: ASCE 7-05; Pr=20.0 psf (roof live load: Lumber DOL=1.15 Plate DOL=1.15); Pg=10.0 psf (ground snow); Pf=6.3 psf (flat roof snow: Lumber DOL=1.00 Plate DOL = 1.00)*

*This truss has been designed for a 10. psf bottom chord live load nonconcurrent with any other live loads.*

** This truss has been designed for a live load of 20.0psf on the bottom chord in all areas where a rectangle 3-6-0 tall by 2-0-0 wide will fit between the bottom chord and any other members.*

So what is my live load and dead load?


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## Gary in WA (Mar 11, 2009)

This is easier: http://www.colonie.org/forms/building/bdspanab.pdf
Check inside under your old house rafters, there may be a purlin bearing on an inside wall. 
Add a short leg or wall under each rafter to this roof area above the purlin to reduce the span/size of the new rafters. Page 39: http://books.google.com/books?id=iw...um=3#v=onepage&q=cutting floor joists&f=false

Easy way to get your angle: Fig. 2-62: http://books.google.com/books?id=-U...s_brr=3#v=onepage&q=shed roof framing&f=false 

Be safe, Gary


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## my5sons (Oct 29, 2008)

GBR,

My existing house roof is 2x4 manuf. trusses as well. I don't believe I will be able to do the knee wall. Believe it or not, there is no load bearing wall in this area of the house. 

Lastly, that rafter table from colonie doesn't come close to the measurements I have. I'm spanning 9 ft 6 in with a 2x6 that *the truss designer told me to use* to tie in the mono trusses @ 24" on center.


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## Gary in WA (Mar 11, 2009)

Wow, that table is wrong. Sorry.... Your trusses have 20# LL, 6.3 snow load, and 10 DL = *36.3# *psf. This table, the third one down, is right close------- 20# LL, 15 DL = *35# *psf: http://www.mcvicker.com/resguide/page013c.htm 
(2x6- 24o.c. - 10'5"span)
Be safe, Gary


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## natemclain (Dec 27, 2007)

*Any pictures & update?*

Curious how the project has been?

Any pictures you can post?


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## my5sons (Oct 29, 2008)

I can't believe I never updated everyone. I received some good help from here and a couple of other forums. I sold the house in 2014 and moved to Colorado. Here are the photos of the finished product.


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## keymaster (Jul 28, 2015)

my5sons said:


> I have a 4/12 pitch on my current roof, which really sucks because if I build the shed style roof, the most I can get out of it is 3/12. I plan on using architectural shingles.


4:12 is the min. pitch that will carry a warranty for an asphalt-shingle roof. (There may be code restrictions as well.) 

My suggestion is to truss both, not just one. Get a pitch you can work with and then you have lots of options.


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## my5sons (Oct 29, 2008)

I ended up with a 3/12 pitch and put down grace barrier on the first layer. Warranty on shingles is pretty much BS, but their minimum was 3/12, so I was fine with the underlayment and shingles.


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## keymaster (Jul 28, 2015)

It looks like you made a substantial improvement, quite nice. Great looking porch. Warrranty doesn't matter if you are flipping, right? (We need a way to revive old threads that doesn't cause others to unwittingly answer.) When did you sell?


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## my5sons (Oct 29, 2008)

Thanks, I actually didn't flip it, it was my personal residence for 10 years. I fired the contractor and built it myself. I ended up replacing the wooden railing a few months before I sold it. 

What I mean by the warranty is that I have never seen a shingle manufacturer honor their warranty. Do they really do that? Usually (from my short experience) they find an excuse as to the smallest detail about whether or not they were installed to specs. 

I did LOTS of research and found that GAF warrantied the shingles for a 3/12 pitch (low slope), but nothing less than that, so I was good. I believe the underlayment was required in the valleys and on the low slope, which is what I did. I sold the house in June of 2014.


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