Gutter Guidance

[Dustoff 35]

Its time to install gutters on my garage. I don't have anyone in the "Buddy Network" that knows or can recommend anyone. I may have to go the dreaded Yellow Pages route on this one. You never know what you're going to get when you crack open the phone book...

Any guidance on gutters and installers? Is there a material thickness I should be looking for? Do they generally charge by the foot? Is there some roof area calculation that determines proper sizing? I already know that we need some type of leaf guard, we have "Leaf Relief" shields on the house.

It should be a pretty simple install, a 46 footer across the front with one downspout and a 44 footer across the back, also with one downspout.

Thanks guys.

 

[Junkman]

Basic rule of thumb is that a gutter will only hold as much water as it can dispose of quickly. If you have only one downspout, your gutter will quickly fill, and slowly empty. Once the gutter is full, it is no longer effective for the purpose it was designed. If you want only one downspout, then don't waste your money on a gutter. My rule of thumb is one downspout for every 12' - 15' of gutter. I have a 40' gutter on my garage, and it takes 5 downspouts to keep the gutter empty in a downpour. I also have made the mistake of getting that gutter made on sight. Most gutter machines that come to your home are only 4" gutters. I have commercial gutters on the rest of the house, which are 6" gutters. The installer that did the rest of the house had gone out of business, so like you, I opened the phone book. Harvey Industries sells the 5" & 6" commercial gutters that they form in the warehouse. Problem is getting such a long gutter home. Shop around till you find someone that can make the larger gutters, and uses the heavier material. A well installed gutter should last almost forever with todays modern material, if it is installed properly. Calculate the total roof surface so you will have an idea as to how much water will fall that needs to be collected. I found the following information on surface collection...

Every 1mm of rain that falls on every square metre of roof equals 1 litre that could be collected.

So the formula is:

1m x 1m x 1mm = 1 litre

Example:
160m² of roof x 5mm rain = 800 litres
250m² of roof x 15mm rain = 3750 litres

 

[Wardster]

Open the phone book and find someone who does continuous spouting in your area. Ask them how they connect it to the building as you should steer clear of nails (hidden screws are the best). You pay for both gutters and downspouts by the linear foot. It's not my place, but if it were I would install a downspout at each end as it is cheap insurance.

-Wardster

 

[Kevin54]

I also have made the mistake of getting that gutter made on sight. Most gutter machines that come to your home are only 4" gutters.

In our area, standard is 5" and they can change to larger for commercial. What type of pitch do you have that you have 5 downs for 40'? Sounds like overkill to me. My garage is a 4/12 PITCH @ 40' and have one down and have no problem whatsoever with drainage. If it a super horrendous downpouring gullywasher that floods fields in about 30 seconds flat, then a gutter doesn't do you any good anyways.

 

[RickP330]

Make sure the gutters are one peice and bent on site (from a roll of aluminum). Spliced pieces do not work and look crappy.
RP

 

[kbs2244]

I am with junkman on this one.
Oversized and thicker material done onsite with at least 2 oversized downspouts.
Use his formula.
Length is only half the problem. You need depth as well to get area.
You should design for the fast and furious 90 second sky dump.

 

[PhantomEB]

I would do dumps at each corner, not sure how your yard, etc is but I have already told the wife, with enviromental thinking in mind (tones down arguements about my hobbies) into rain barrels to water the grass and flowerbeds with.

Hell its cheaper on my wallet so why not! PLUS I fully intend to empty those barrels while watering with a 110V sump pump.

 

[kbs2244]

I checked the PIC on your build thread.
For sure, over sized gutters and double oversized downspouts on the left side.
With well defined run off swales.
You may only need the once a year, but you will be glad when it happens.
Water is a real pain when it is where you do not want it.

 

[Junkman]

I checked the PIC on your build thread.
For sure, over sized gutters and double oversized downspouts on the left side.
With well defined run off swales.
You may only need the once a year, but you will be glad when it happens.
Water is a real pain when it is where you do not want it.

I would space the downspouts evenly across the entire length of the gutter. The idea is to remove as much of the water as fast as you can. If you put all the downspouts on one end, then the first will take the majority of the water, and the balance will need to jump the gap between the first and second downspout. If you place one at each end, and one in the middle, you will remove more water faster than if you put all 3 at one end. The water entering at one end of the gutter would have to travel the entire length of the gutter to get to its exit with your method.

 

[Kevin54]

I would put one down at each end (the guys that hang the gutters will put the high part of the gutter in the middle of the building) and run it out. What i would NOT DO is bury any corrugated pipe to drain the water away. Reason being is that you are in a woods. Any leaves, seed pods (whirlygigs) that would find their way into the gutter would get caught up in the pipe. I have mine buried but do not have trees around to fill them up.

 

[larry4406]

When I built houses and had to divert water away, we always used smooth boore 3 inch SCH 40 plumbing pipe or smooth bore thinwall PVC drainage pipe rather than the corrugated black draintile type (without perforations). The corrugatsions will trap debris. Make sure the end is daylit.

 

[kbs2244]

Most installers I have worked with just make them level for looks reasons if not told otherwise. I think the recommended slope is ¼ inch per 10 foot of run. That would be a full inch on a 40 foot run. That would be noticeable. Go with it if you think you can live with the appearance.
My reasoning on the double downspouts at the left is to give plenty of drainage to dump all the water. The left is the low side of the lot. The right side is the high side and any water from a right side downspout will just run across the driveway. Same problem with downspouts between the doors.
The whole purpose of gutters is to make it easy to get water away from the building. If you are just going to dump it on the driveway you might just as well not have them.
I agree about the smooth vs. corrugated pipe, but with all his trees I would avoid any pipe at all. A well defined swale will channel a lot of water and can be cleaned out with a leaf blower in about 5 min.
He has a pretty good slope away from the building on the left side. That is where the water is going to want to go. Our job is to just help it along a bit.
BTW, I would do the same on the back side.

 

[PhantomEB]

Myself I be thinking WHO CARES about how noticable it is, looks aint gonna work as good when the water comes down! CONTROL that water whatever way you can!

 

[powellscooter]

I hung my own, 2 60`of multiple sections, with down spouts on each corner. From Home Depot. They work well enough, but then again I live in AZ. so its not like we get a lot of rain....

 

[DynoDave]

Wow, a timely topic. I'm adding gutters to mine this year, and only want down spouts at one end as well. Interesting reading.

 

[Dustoff 35]

Just got back in town from a fishing trip and read all the posts. Thanks for the input guys. I have a local gutter contractor coming over tomorrow to take a look / give a quote. I already told him that I wanted 6" gutters and large (4" x 3" Is the size, I think)downspouts. I'll set you know what he says...

As anyone who has checked out the pics in my post can tell, I need gutter guards. We have way too many trees not to have them. We have the ALCOA leaf relief guards on the house and are pretty happy with them.

If I need more than one downspout per run of gutter, I'll have to run PVC underground from the uphill side to the downhill side, to daylight. I'll have to run it under the driveway in the front. Should I use SCH 40 to run under the drive or should I upsize?