Porch railing and water drainage

[Kodi Crescent]

I have a rotten set of front porch posts and rails I need to replace.  The current rails are made from 2x4's laid flat with a baluster "ladder" between them.  I'd like to replace these either with a maintenance free material, or at built some others that will be relatively maintenance free.

I'm a bit puzzled as to the flat surface of the railing and support piece.  Much of anything else we build that comes into contact with water has a slope to allow quick drainage or drying.  Is there a preferred way to build standard porch rails so that they shed water more easily?  Am I concerned about something I shouldn't be concerned about?

Thanks!

 

[Cheese]

A number of years ago I made a simple fixture that allowed a 2x8 to be run through a planer at a slight angle. I ran the board through a few times until 1/2 of it was angled, then removed the fixture, rotated the board 180 degrees, reattached the fixture and ran it through the planer again until the entire surface had a slight draft. It worked well... [big grin]

 

[tjbnwi]

Stole this design from @ Brian Campbell.

Tom

 

[tjbnwi]

A little better photo of the baluster landing on the bottom rail.

Tom

 

[Kodi Crescent]

Perfect!  Thank you!  Are those 2x4's you're using?

 

[tjbnwi]

[member=8843]Kodi Crescent[/member]

Yes, cedar.

Tom

 

[Bob D.]

A number of years ago I made a simple fixture that allowed a 2x8 to be run through a planer at a slight angle. I ran the board through a few times until 1/2 of it was angled, then removed the fixture, rotated the board 180 degrees, reattached the fixture and ran it through the planer again until the entire surface had a slight draft. It worked well... [big grin]

The technique that Cheese describes here would duplicate the design of the top rail of an old home I restored years ago. That top rail was made from full cut 2x6 fir and had a double bevel on it yielding a rail ~2" high in the center and 1.5" at the edge and was 5" wide. The underside of the top rail had a drip groove in it so that water would not run under to the balusters but drip off the bottom at the edge. For the pieces of rail I had to replace I duplicated these details, the tough one was the section of curved rail with 54" radius. The drip groove on the under side was used on all the outside stair treads too, and worked well at stopping rain water from running back to the riser. It's easy to make with a router and a square-edge bead bit, a point-cutting plunge roundover bit which is what I used, or a full bead bit. Has held up well as it's been 26 years since I rebuilt that porch and it's still standing.

 

[Alanbach]

Have you considered PVC? It works like wood with woodworking power tools and lasts and lasts. I have replaced most of the brick molding on my home with it as the wood has rotted. It is pretty readily available at home centers in one by, I am not sure about the availability of two by or of a process for gluing up the pvc.

 

[Cheese]

The underside of the top rail had a drip groove in it so that water would not run under to the balusters but drip off the bottom at the edge. For the pieces of rail I had to replace I duplicated these details, the tough one was the section of curved rail with 54" radius. The drip groove on the under side was used on all the outside stair treads too, and worked well at stopping rain water from running back to the riser. It's easy to make with a router and a square-edge bead bit, a point-cutting plunge roundover bit which is what I used, or a full bead bit. Has held up well as it's been 26 years since I rebuilt that porch and it's still standing.

Thanks for reminding me about the drip groove  [thumbs up]  that's almost more important than the bevel on the top.  [eek]

I've even cut the drip groove in NY Bluestone treads for outdoor use on cement steps. I just ordered some 1 1/2" Bluestone for some more veneering and drip grooves will be cut into those before installation.

 

[Kodi Crescent]

Have you considered PVC? It works like wood with woodworking power tools and lasts and lasts. I have replaced most of the brick molding on my home with it as the wood has rotted. It is pretty readily available at home centers in one by, I am not sure about the availability of two by or of a process for gluing up the pvc.

I've considered it.  I'm a bit puzzled about how well it would hold it's weight over a 64" span.  It seems like it would sag.  Am I missing something?

 

[tjbnwi]

Have you considered PVC? It works like wood with woodworking power tools and lasts and lasts. I have replaced most of the brick molding on my home with it as the wood has rotted. It is pretty readily available at home centers in one by, I am not sure about the availability of two by or of a process for gluing up the pvc.

I've considered it.  I'm a bit puzzled about how well it would hold it's weight over a 64" span.  It seems like it would sag.  Am I missing something?

PVC will sag unless it hollow with an aluminum channel in it.

Tom

 

[Alanbach]

It’s a great question that Unfortunately, I don’t have the answer to. 64” is a significant span so I would be concerned too. I am a hobbyist so my experience is limited. I just know that when I have used it to replace wooden molding in weather prone areas of my home it has performed really well. I live in Houston, Tx. And we get a lot of rain here. The material works like wood (only with white dust that goes everywhere), paints well (with the correct primer), takes screws well and ostensibly lasts virtually forever. You would have to do your own research regarding pvc rail systems. I am pretty sure that they are out there I just don’t know where to point you to.

 

[Koamolly]

Timbertech makes a nice composite system but style might not fit everywhere.  I live in a rainforest so really wet area.  My place is very rustic, old growth rough redwood, cider and fir.  I’ve rebuild railings twice with redwood but now switching to ipe.  I could bevel, slope, cut drip channels etc., but it will probably stay or get wet anyway. Plus anywhere geckos, insects and spiders can nest, lay eggs, they will.  I epoxy end grain, epoxy or imbed joints in polyurethane caulk.  Or design in gaps between miters and joints so they don’t retain water.