Building a back porch - advice needed

[robinson46176]

Methinks the screening will be adequate for that purpose(and the smoke will help drive off the long nosed female insects).

A good place for a ceiling fan. Nice breeze, keeps air fresh and moving air discourages biting flies and skeeters that may sneak in the door when open. Very cheap to operate.

[JPG]

A good place for a ceiling fan. Nice breeze, keeps air fresh and moving air discourages biting flies and skeeters that may sneak in the door when open. Very cheap to operate.

One of these on each end should be 'adequate'.


http://www.bigassfans.com/residential/index.html

GEE! Is that a boat? or one fancy boathouse/dock?

[Ed in Tampa]

1-2x12 costs more than 2-2x6. Assuming you would still double the 2x12 on the sides, than means 4-2x12 vs 6-2x6>> You could buy more than 8-2x6 for the price of 4-2x6'. However the 2x12 are more than 4x as strong as the 2x6. Thus 1-2x12 is twice as strong as 2-2x6! So- - - using a 1 2x12 on each side costs more, but is twice as strong.

The center support is recommended by me. This reduces the flooring span to 5'. Also being centered under the freezer is ideal. I think you would be more satisfied having the center support. Yes the doubling of the center support would be my recommendation. It makes no sense to make it weaker than the outer ones. The objective is to provide equal strain reduction(flexing) across the surface.

I would provide a plate to secure the support beams to the posts and to tie the joint together.(outer surfaces)


Now considering all that you have added to the mix. I suggest the following!

6x6 posts on plynth with a single notch centered to accept the support beam(s). Or a single notch on one side of the post. 10' between posts along the longer sides/center(as per yer sketch)

2x12 support beam(single) resting on the shoulders cut in the 6x6 posts. two bolts per 2x12 end through the 6x6 above the shoulder.(use washers)

Three beams(Include the center beam).

The cantilevering of the truncated area(overhang) is acceptable considering the closeness of the supporting beam. Box in the ends of the joists to prevent them rotating(like bridging does). Short spacer inside, continuous piece outer.(box sill)

Box in the outer ends of the jousts also. Main thing is to prevent the joists from rotating. Bridging over the center beam(or blocking).

How ya gonna tie the joists to the beams? Consider hanging the joists from the outer beams rather then setting them on top. Leave them on top of the center beam. Attach a 2x6 shoulder to the inside of the 2x12 for the joists to rest upon(5 1/2" from the top). This will eliminate the need to box it in(the 2x12 becomes the outside of the box). Increase the notch in the post to include the shoulder 1x6(it is 1/2" shallower) and cut it on the inner side. That would leave 2 1/2" for super structure attachment etc. on the outside. This would require the center beam be 6" higher than the outer ones.

It is an open porch(screened) and is subject to rain accumulation. Provide a minimal outward slope and weep holes in any sides attached on the outer edge. Make sure any water can totally vacate the weep holes. Yes a screen will be needed to keep those pesky blood thirsty insects out!

Definitely more than enough for ONE post!!!

Built this way I would say you could park a tank on the it.

Yes 2x12 are more expensive than 2x6 but you would only need 16
and plus the 4 or 8 depending on length 2x6s doubled for the ends

If you built is your way your would need 16+ depending if he goes 12" on center for the freezer area 2x6's plus 6 or 12 depending on length 2x6 plus 4 extra 4x4 for the center support.

And I ain't real sure you couldn't use 2x10's. If someone has a general construction guide they could verify but I think for a 10 ft span 2x10 may be sufficient.

[heathicus]

Priced it out and using 2"x12" boards for the floor joists is just too expensive - even eliminating the center support beam.

I didn't specify it anywhere, but in my Sketchup model, I had used 2"x8" boards doubled for the support beams and 2"x6" for floor joists. How does the strength of double 2"x8"s compare to a single 2"x12"? There isn't much difference in price.

A 6"x6" post is over twice the price of a 4"x4" post.

I had planned on boxing in the ends of the floor joists and even included that in my Sketchup. But I forgot to unhide it when I was taking screen shots.

The least expensive option I've come up with so far, that still appears structurally sound to me (but I have as much engineering training as William Hung has had singing instruction) is 4"x4" posts and single 2"x12" support posts bolted to the posts. Will this last a few years?

[Ed in Tampa]

Priced it out and using 2"x12" boards for the floor joists is just too expensive - even eliminating the center support beam.

I didn't specify it anywhere, but in my Sketchup model, I had used 2"x8" boards doubled for the support beams and 2"x6" for floor joists. How does the strength of double 2"x8"s compare to a single 2"x12"? There isn't much difference in price.

A 6"x6" post is over twice the price of a 4"x4" post.

I had planned on boxing in the ends of the floor joists and even included that in my Sketchup. But I forgot to unhide it when I was taking screen shots.

The least expensive option I've come up with so far, that still appears structurally sound to me (but I have as much engineering training as William Hung has had singing instruction) is 4"x4" posts and single 2"x12" support posts bolted to the posts. Will this last a few years?

If that is case then I would use double up 2x6 in place of the single 2x12 support rails bolted to the 4x4. That will be stronger especially if you stagger the joints. Did you price out 2x10"s? I'm fairly certain 2x10 are okayed for 10 foot span.

[iclark]

you should double-check the safe spacing for your grill. IIRC, mine wants a couple of feet from any flammable wall. we have had some apartment fires around here from people BBQing on the balcony and catching the siding afire. at least one of them thought that aluminum was non-flammable although most have been vinyl siding.

I see that you used a gas grill in sketchup. please do not even consider using a charcoal grill on a covered porch that small. DAMHIK

[JPG]

Priced it out and using 2"x12" boards for the floor joists is just too expensive - even eliminating the center support beam.

I didn't specify it anywhere, but in my Sketchup model, I had used 2"x8" boards doubled for the support beams and 2"x6" for floor joists. How does the strength of double 2"x8"s compare to a single 2"x12"? There isn't much difference in price.

A 6"x6" post is over twice the price of a 4"x4" post.

I had planned on boxing in the ends of the floor joists and even included that in my Sketchup. But I forgot to unhide it when I was taking screen shots.

The least expensive option I've come up with so far, that still appears structurally sound to me (but I have as much engineering training as William Hung has had singing instruction) is 4"x4" posts and single 2"x12" support posts bolted to the posts. Will this last a few years?

1 2x12 is slightly stronger than 2 2x8. However the doubled 2x8 have twice the foot print on the post. If shouldering the joists to the beams, the 2x8 only allow for a 2" shoulder(not enough). You would have to notch each joist. . . . . 2x12 is simpler/stronger ... than 2 2x8.

How long it 'lasts' depends upon what you put on it and weather effects.

There is more than twice as much wood in a 6x6 as in a 4x4.

I prefer a shoulder support and bolting only to maintain position. I do not like using bolts for 'support'. A 4x4 is pretty narrow for two rows of bolts, but they could be done that way. If shouldered, I think 3/8" bolts would be adequate. Only the center 'joint' is 'crowded'. A double 4x4 there would eliminate the 'crowding'.(or use a 6x6 for the center posts).



BTW 2 2x6 is NOT as strong as 1 2x12. The 2x12 is more than twice as strong!

[Ed in Tampa]

BTW 2 2x6 is NOT as strong as 1 2x12. The 2x12 is more than twice as strong!

JGP40504
I bow to your knowledge but after rethinking what he wants and for how long he wants it doubled up 2x6 spanning less than 5 feet between the 4x4 post is more than strong enough. Likwise sitting 2x10 spaced 16" on center is strong enough to span 10 feet without a middle support.

He might also consider sitting the whole thing on the ground using pressure treated 2x4's and building steps down to it. That would be by far the cheapest and since he only needs it for 5 years why spend all the money to make is anything else.

As for 4x4 or 6x6 posts most of the force will be compression and 4x4 is enough. Now if you want to do cut outs 4x4 could be a problem but why even do this? Just through bolt one 2x6 on either side of the post it won't go anywhere in 5 years. If you don't feel comfortable with that then use a metal "H" bucket set atop the 4x4 that straddles the 4x4 and straddles the double 2x6. Drive nails in every hole in the bucket into the each side of the 4x4 and into the 2x6.
That will hold for 5 years or longer.

[JPG]

JGP40504
I bow to your knowledge but after rethinking what he wants and for how long he wants it doubled up 2x6 spanning less than 5 feet between the 4x4 post is more than strong enough. Likwise sitting 2x10 spaced 16" on center is strong enough to span 10 feet without a middle support.

He might also consider sitting the whole thing on the ground using pressure treated 2x4's and building steps down to it. That would be by far the cheapest and since he only needs it for 5 years why spend all the money to make is anything else.

As for 4x4 or 6x6 posts most of the force will be compression and 4x4 is enough. Now if you want to do cut outs 4x4 could be a problem but why even do this? Just through bolt one 2x6 on either side of the post it won't go anywhere in 5 years. If you don't feel comfortable with that then use a metal "H" bucket set atop the 4x4 that straddles the 4x4 and straddles the double 2x6. Drive nails in every hole in the bucket into the each side of the 4x4 and into the 2x6.
That will hold for 5 years or longer.

I agree with yer facts, I just do not like supporting with either bolts or nails. The hanger does provides the support, and the nails hold its position.

With the shorter span(5') it will be less 'springy' and do not forget that concentrated load of the freezer.

Yep there be many ways to skin a cat and varying degrees of defining the task. Only Heath can decide what he will do. We both(and others) have provided alternatives and input for mind crunching(that be what he asked for).

Go Heath, GO!:)

[heathicus]

Yep there be many ways to skin a cat and varying degrees of defining the task. Only Heath can decide what he will do. We both(and others) have provided alternatives and input for mind crunching(that be what he asked for).

Indeed! And I am most appreciative. I no longer feel as lost as I did!