Rain diverter

[SailinAway]

I'm preparing my house to be painted. I just had a 6' x 12' section of rotten siding replaced on the rear. The cause of the rot is rain falling from the roof onto the small roof over the back stoop and bouncing back onto the siding. Note that the rain is falling from two different levels due to the setback of the dormer.

There are no gutters on the rear of the house. They were removed by a previous worker who told me they were causing ice dams (removing them made no change in the ice dams). Strangely, the siding to the right of the door was not affected. We removed all rotten siding and underlayment and covered the new plywood with bituthene.

To prevent this section from rotting again, I would like to place some kind of diverter on the little roof over the stoop. Any recommendations as to the type, material, and placement of the diverter? I will address the lack of gutters in a later project as I can't do everything at once. Thank you!

[John Mercier]

Where would you be diverting it to?

[SailinAway]

Originally Posted by John Mercier

Where would you be diverting it to?

Away from the house is all I know. If I go bankrupt from increasing energy costs I could divert it to a rain barrel, I suppose. As a matter of fact, that's not a bad idea.

[John Mercier]

A diverter is usually aluminum and placed within the shingled portion.

A section of gutter... even if you chose to remove it in the winter... could direct it toward either a rain barrel or a downspout with a splash block or piping system that would move it away from the foundation.

The gutter above the doors at our Bristol location freezes solid every year and creates problems... we intended to extended it and add heat cables.

But I think we are better off just removing it for the winter and using sand and salt.

[fatlazyless]

Home Depot in Tilton has do-it-yourself rain gutters with a downspout that drains the water into a 100-gal rain water storage tank for watering the lawn & garden ...... later on, some time .... http://www.homedepot.com/p/100-Gal-G...5964/316107600 .... for what seems like a reasonable price.

[Slickcraft]

You could install a diverter on the roof of the shed dormer made of flashing like in this photo. It could keep water from hitting the roof over the stoop. This, however, may cause additional splashing onto the lower 1st floor siding. It already looks like paint pealing there. Looks to me like gutters is the solution.

One way for damage to siding: the flashing at the intersection of the little roof with the siding may have channeled water under the siding.

Alan

[DickR]

The places where a roof slope intersects a vertical wall must have step flashing on the wall at each course of roofing, or an equivalent installation for keeping water from getting under the courses of wall siding. At each place where an intersecting roof slope ends in the middle of a wall section, such as at the upper right corner of the red rectangle drawn on your photo, there should be kickout flashing at the lower edge of the roof section, to throw the water out away from the wall siding below. Do a search on "kickout flashing" and you'll see a great many commercial products and videos showing installation. You can fabricate your own flashings from sheet metal.

Here is but one reference, with video and diagram: https://www.americanflashings.com/jd-out-flashing

Here is another article, by Mike Guertin, a frequent contributor to magazines like Fine Homebuilding and Journal of Light Construction: https://www.jlconline.com/training-t...n-overlooked_o

[SailinAway]

Originally Posted by DickR

The places where a roof slope intersects a vertical wall must have step flashing on the wall at each course of roofing, or an equivalent installation for keeping water from getting under the courses of wall siding. At each place where an intersecting roof slope ends in the middle of a wall section, such as at the upper right corner of the red rectangle drawn on your photo, there should be kickout flashing at the lower edge of the roof section, to throw the water out away from the wall siding below. Do a search on "kickout flashing" and you'll see a great many commercial products and videos showing installation. You can fabricate your own flashings from sheet metal.

Dick, thank you for this information and the links. So I would place kickout flashing in this area?

[SailinAway]

Dick, is this the right shape? https://www.homedepot.com/p/Amerimax...KOWH/203208108

Install like this?

[DickR]

If the damage to the wall is the red rectangle to the left of the door in your first photo, then the place where the lower edge of the roof over the door meets the wall is indeed where the kickout ought to go, as indicated in your second photo. However, that shot from the Home Depot seems to show installation of the flashing over the wall siding, with caulking to (hopefully) seal the top of the flashing to the siding. When at all possible, roof and wall covering layers ought to be "shingle-lapped", with all successively higher layers lapped over the tops of lower layers. This is shown in the JLCOnline link I gave. Actually doing this in a retrofit situation can be difficult, but sometimes getting a long-lasting installation does involve a bit of "wall surgery." You probably can find some decent retrofit videos.

[SailinAway]

Thanks, Dick. The how-to photo was from a different website. I think my handyman would not be pleased to have to lift up any siding, which he just finished installing. I'll study your other link.

[John Mercier]

The kick-out would be under the eave on the stoop, and on the sidewall of the dormer. It wouldn't hurt, but will not stop the water from splashing back against the siding once it hits the ground.

Sooner or later, you will need gutter the total length of the main roof.

The paint peeling under the window suggests that water may be getting behind the siding... and that something like a hydrogap or homeslicker was not used.
I can't tell from the photo if the clapboard was properly primed on all faces, or if it was properly caulked.

[SailinAway]

Originally Posted by John Mercier

The kick-out would be under the eave on the stoop, and on the sidewall of the dormer. It wouldn't hurt, but will not stop the water from splashing back against the siding once it hits the ground.

Sooner or later, you will need gutter the total length of the main roof.

The paint peeling under the window suggests that water may be getting behind the siding... and that something like a hydrogap or homeslicker was not used.
I can't tell from the photo if the clapboard was properly primed on all faces, or if it was properly caulked.

John, the worst rotting was at about the height of the window, right where you would expect water to spill from the entrance roof onto the siding. It wasn't as bad at ground level. I have stones next to the house to help with splashback (I hope it helps). The area where the dormer meets the roof seems less likely to send water to the affected area as it would flow straight down and out, less likely to the right. Still, you and Dick make a good point about the need for flashing where the roof meets a sidewall.

Yes, the new siding was primed on all faces. Did it myself, two coats. Yes, everything was caulked---I finally found a skilled handyman. This is a 1929 house, so other than this new siding, the rest of the house doesn't have any special waterproofing. The reason for what looks like peeling paint is that I've started scraping that wall to repaint the whole house. Gutters are on the to-do list.

[DickR]

Here is another article, showing a custom formed flashing for up where the dormer wall meets the roof: https://www.greenbuildingadvisor.com...-roof-flashing

And another: https://www.finehomebuilding.com/pro...keep-water-out

[John Mercier]

The picture shows what appears to be missing paint from the siding under the window?

[SailinAway]

Originally Posted by John Mercier

The picture shows what appears to be missing paint from the siding under the window?

Good eye. That was the one error the worker made---he accidentally nailed the board unfinished side up. Maybe there was a little bit of rot there. The other patches are places where I'm scraping.

[John Mercier]

If it was primed on all faces, he shouldn't have had any side that could be applied ''unfinished'' side up.