Hello all, I have been reading these forums a lot while building myself a 12x18 little house on a remote river in North West BC. I have learned a lot here and put it to use in my build.
I am looking for some feedback on how I built my porch.
I added a porch across the end facing the river and am now second guessing if it will be strong enough to take a good snow load or should I beef it up. A few details of contruction - The floor joices are 2x6 on 16" inch centers. The cabin end are attached with joice hangers to a 12' 2x6 the rests on the main beams and is spiked to the end floor joice of the cabin. The outboard end of the joices rest on a 4x6 (2 2x6+1/2ply spiked every 8"). The 4x6 is supported by vertical 4x4 on 48inch centers. The vertical 4x4's having same footings as the cabin, 16x16x2" cement pads with pyramid blocks. The roof has a fairly low slope. With a 8 ft span the differance in height from one end to the other is 18". The roof is metal on 1x4 puorlins on 12" Centers. Rafters are 2x6 on 12" centers. Cabin end of rafters are rest on 2x4 ledger that is nailed and has 1/4" lag bolts into the wall studs every 16" across the front of the cabin. The ledger is also supported by 4 2x4's that are spaced accross the front of the cabin and are nailed into wall studs. The bottom of these 2x4's sit on the porch floor directly over the 2x6 that the floor joists are hung on. Outboard end of rafters rest on 4x6 (built same as deck beam) Roof beam is supported on 48" centers with 4x4's. The roof supports are placed directly over the floor beam supports so the load is carried straight down to the footings. This is a remote area that I cannot get to most of the winter. It can get several feet of wet snow and then get rained on perodically during the winter. Should I beef is up with tempory beams for the winter or is it strong enough?
Thanks for any input
Stew
Stew
It sounds very strong, but it would likely take an engineer or architect with knowledge of the snow loads and local conditions to really tell you if it would stay or not.
Looks like a little over a 2/12 pitch so likely will not shed the snow and will have to support it.
Do you know what they consider the snow load to be in your area - you could make a guess on the needed strength from there.
Also it may help if you check similar construction in a similar area. Sorry I'm not of more help. I'm just a contractor.
Without engineering any of this is sounds pretty sturdy.
A 2x6 @ 12' o/c rafter layout for the porch can span at least 10' and often up to 13' with good lumber while carrying a 30psf snow load. If you are in coastal BC you are unlikely to get more than that. (At 50psf the same roof can span about 9').
John, I have a carport roof that is 2 x 4 rafters spans 8 ft and they are 16" o/c. They are attached to the ledger with hangers and sit atop of double 2 x 6's that are supported by 4 x 4 posts 8 ft apart.
I live in Upstate NY how much snow load will this handle ?? I try and roof rake it when it is heavy but I have left it before and it seems ok, whacha think ?
Would it be safe if I left it ?? It is 5 ply fir plywood decking
There is a rafter span calculator in referral links - http://countryplans.com/smf/index.php?topic=2729.0
With Eastern Softwood it shows 7'1 span at 20 lbs snow load 10 lbs dead load - so looks marginal to light depending wood you have and the snow load you actually get, I think.
Yes, that roof would be underdesigned for modern construction and codes. That doesn't mean it couldn't hold up for many years, but you don't have the safety margin you should have.
Getting a midspan beam under the joists is probably difficult (but a good solution if you can find a way to support it). You could also double up the 2x4 rafters with sister rafters nailed to the ones you have.
cvcman Not sure hich part of upstate NY you live, but I have a cabin in Redfiled area and the snow loads up there run anywhere from 60 to 80.
Well a couple of my buddies were up the river last week and tell me my porch survived just fine. There must have been a lot so snow this year becasue as of Easter weekend there was still 7 ft of wet snow on the ground in the open. Only about 3 feet still left in the timber around my cabin. I going up next weekend to do a little work and spring clean up.
Glad to hear the porch made it through the winter.