Deck Construction, Pro advice

[70SATMan]

To you Pros out there, I'm in the process of designing a replacement deck for the back of my 60's Cali Ranch. The property is sloped and floor elevation at the back is approx. 5' from grade.

The old deck (6' x 44') along the whole back of the house was off cantilevered beams from the under floor post and beam construction. That deck was cut away because of termites and the PO didn't want to add the square feet of the deck to the cost of tenting.

So, I can build the new deck either free standing or use a ledger off the house wall.
We have had some settling of the rear foundation on one corner, have a decent clay layer around 2' down. Stand alone would isolate pressure from differing rates of expansion for sure.

At one time, I thought that a free standing deck not attached to the house could be built without permits. Having said that, I plan on some pergola/trellis action that would follow, either attached or not attached to the house.

I can build either just as easily, not a problem. What's the consensus from the pros, or at a minimum, pros and cons that I might not have thought of??


I'm also considering Ipe for the deck material but, do most going that route, do everything (except framing) in Ipe?

[VINMAN]

You can't attach a ledger to a cantilever, without doubling the house floor joists, and adding blocking between them. Its,a huge pain in the azz to do. I usually talk my customers into doing the deck freestanding.
Not sure where you are, but here in NJ you still need permits for a freestanding deck

[70SATMan]

The original cantilevered deck is gone back to the wall plates. New ledger would be on the rear wall of the house.

[look 171]

OK, that may work.

I just got my kids to do this as our covid project. Red Balau aka mangaures or Cumaru all come from same family as Mahogany only Red Balau is much harder but not near as hard as Ipe but a tad more then a dollar per lin. foot for a 5/4 x6" decking.

I over build everything almost all the time so my floor joist are 4x8 and half of the lower deck is 4x12 and the other is salvaged metal roofing truss from an industrial building. The span is over 17' and they run the length of the house. There's no bounce on both the lower deck and upper. As a matter of fact, I am going to try and finish up the hand railing after I get off the computer and pry the cold hands off the key boards from the games.

Edit

Ipe is a bit more then a buck per lin' compared to the others.

I also suggest using pressure treated especially up where you are, its always wet.

[look 171]

My suggestion is to attach the deck to the house. It would be too much weight because its distributed along the entire length of the home. You home sounds like mine, the back of the house slops down hill? The lower decks have not moved 1/2" for the 17 years I built it (finished it before my first kid came so he can play out there). I dug these large footings knowing it will never move. They are 36" x36" up to 3-4 foot deep. I know, nuts even though my hill is on bed rock but the top soil isn't too great.

My suggestion to you is to take care of the slight sag on the corner of the building. Have someone under pin that corner so its more stable. Depending on accessibility, it shouldn't cost too much money to stop the settling.

How long is the deck going out, 6'?

[VINMAN]

How far out from the house to you want to go with the new one?


.

[Bill Douglas]

Someone mention foundations?

I used to do the computers for a company called Robinson Seismic who invented/designed/had patents on rubber and lead foundations for big buildings to help them survive earth quakes. I conversationally mentioned to them I was redoing the foundations on my old 1899 cottage. They said dig a hole, not deep but wide and make the bottom of it concave. By this they meant deeper on the outside of the hole than in the middle. They said almost everyone makes the mistake of having a "convex" shape to it and the poured concrete forever sinks into the ground with the point in the middle acting like an arrow - if you can imagine that. Whereas a concave bottom to the poured concrete foundation "stacks up" the dirt and compresses it as it tries to sink into the ground.

[70SATMan]

Yep, the whole property slopes gently from the street towards the back property line and am planning PT for the entire frame. I think it's actually code for us now.

I'm not going to run the new deck corner to corner of the house like the old deck was, I'm coming in around 5-6' from both corners so, more like 30-35' at the longest. 6' out from the house at the ends like the original deck but, in the middle, I'm going to kick out to 10-12' for outdoor table seating. The deck access will be just off the 10-12' square accessed by a 5-6' slider. Currently, the deck access is on the dining room side of the house but, we have a master plan in the works for kitchen blow out remodel so, I'm going to move that doorway to the living room side.

I also plan to move the hot tub into one of the nooks created by the 10-12' main section of the deck (at ground level) and incorporate a privacy panel along the other end towards the neighbor's house. Possibly a ground level platform around the hot tub and the landing for stairs off the deck down into the yard or flagstone.. Haven't decided that part yet.

I've just been vacillating on the free standing or not. I do like the idea of not pouring as many footings, LOL. Good suggestion on the problem corner, really should address that sooner rather than later. It's down about a 3/4 inch in that corner and we have a couple of foundation cracks on both sides of the corner from the '89 Quake. It's only been in the last five years that its gotten worse.

Still in deck design phase. First I've got to finish the last 50' of fence I'm replacing. Started along the front last summer/fall (covid project) to create a front courtyard and now continuing down the side..

[look 171]

That's an easy one if only 6'. I would attach the deck to the house and not free standing. Really, you think 6' is enough? That's just enough for two people to stand there and have a conversation. I will try and get you a pic of my almost finish deck my 13 and 15 year old built tomorrow. Its dark out now.

You doing this yourself?

Underpinning that corner isn't difficult, but it is hard work. Dig a hole depending on how far it dips, normally, we going about 3' from both directions on the corner and under house. excavate under the foundation and go down about 4'. Epoxy rebars to existing footing. Pour that puppy and you should be done. If you like, the building can be jacked up an inch with minimal interior damage. You are basically reinforcing that corner with a giant concrete pad. I have done many hill side home like it to keep it stable. Again, I have not seen the house but that's the general idea.

There's also Ram Jack. I am not sure about your building dept's approval with them. LA is a no go last time I check. If they did, I would have made millions with all the hill side home we have that are falling down the hill. Its much cheaper and so much less work. There's a guy out of the central cost that do that type of work. I wanted him to jack up an apt unit I was interested in buying at Taft but the deal fell through.

[Bill Douglas]

Originally Posted by look 171

, the building can be jacked up an inch with minimal interior damage. .

Good game plan.

I releveled my old cottage myself, with the above described foundations, and it came out really well (25 years later and still good). One corner of the house came up 75mm (that's about 3") and the house was fine in regard to doors closing and other levels. So it's worth doing yourself. I had three or four small bottle jacks. the sort you jack a car up with. The house weighs very little per square meter.

[look 171]

Originally Posted by Bill Douglas

Good game plan.

I releveled my old cottage myself, with the above described foundations, and it came out really well (25 years later and still good). One corner of the house came up 75mm (that's about 3") and the house was fine in regard to doors closing and other levels. So it's worth doing yourself. I had three or four small bottle jacks. the sort you jack a car up with. The house weighs very little per square meter.

There's a bit more to that but not much. Lifting a simple house described and underpinning foundation is more donkey work then anything else requiring little skill but a little understanding of how things work. That corner can be lifted with a big beam and two jacks over a pad. This way the concrete can be floated jsut right up to the bottom of the plates. Depending if his house has cripple walls and if its slab on grade. Different approach is needed.

About the same time I built the deck downstairs, I replaced the entire foundation on one side of the house. I bought it knowing it was sagging about 3". Price we all pay living on the hill side. Can't beat gravity. Its been straight and true ever since. I poured lots of concrete under there with much bigger footing suggested by my engineer. I took a few months off, did lot of the work myself, with a couple of my workmen. Had much more energy 15 years ago at 38. With second baby coming, wife doing some of the running around, a budget and too cheap to hire someone, it got done eventually.

[hcoles]

Originally Posted by Bill Douglas

Someone mention foundations?

I used to do the computers for a company called Robinson Seismic who invented/designed/had patents on rubber and lead foundations for big buildings to help them survive earth quakes. I conversationally mentioned to them I was redoing the foundations on my old 1899 cottage. They said dig a hole, not deep but wide and make the bottom of it concave. By this they meant deeper on the outside of the hole than in the middle. They said almost everyone makes the mistake of having a "convex" shape to it and the poured concrete forever sinks into the ground with the point in the middle acting like an arrow - if you can imagine that. Whereas a concave bottom to the poured concrete foundation "stacks up" the dirt and compresses it as it tries to sink into the ground.

That is some good info. right there!

[70SATMan]

I’ve done all my own work over the years and the deck won’t faze me. The whole house is beam on post with perimeter concrete foundation. I think they skimped a bit on the backside foundation as the front and sides are really beefy and we’ve had no cracking there. Cripple walls all the way around with nearly 5’ of crawl space along the back. I actually built a lighted under house storage under there. Sub floor is all 2x8 t&g and with the cripple walls, I’ll go through the walls with a beam across the corner and jack from the outside.

Thanks for the advice on the depths for the underpinning and you’ve sold me on the ledger.

Now you have me second guessing my deck dimensions, lol. Had planned one end for two small chairs and a bistro table and the other end for a lounge chair. Something about the long narrow design with the low ranch lines of the house is still appealing. Maybe one end out to 8’, who knows. With my wife involved in the design, one thing for sure, it’s lible to change several times before I start digging footings.

[flatbutt]

Originally Posted by Bill Douglas

Someone mention foundations?

I used to do the computers for a company called Robinson Seismic who invented/designed/had patents on rubber and lead foundations for big buildings to help them survive earth quakes. I conversationally mentioned to them I was redoing the foundations on my old 1899 cottage. They said dig a hole, not deep but wide and make the bottom of it concave. By this they meant deeper on the outside of the hole than in the middle. They said almost everyone makes the mistake of having a "convex" shape to it and the poured concrete forever sinks into the ground with the point in the middle acting like an arrow - if you can imagine that. Whereas a concave bottom to the poured concrete foundation "stacks up" the dirt and compresses it as it tries to sink into the ground.

Brilliant! I'm getting ready to built a concrete pier for a large-ish telescope and will so do a concave hole.

[Bill Douglas]

Originally Posted by flatbutt

Brilliant! I'm getting ready to built a concrete pier for a large-ish telescope and will so do a concave hole.

Yeah, it does make sense when you think about it. I've followed Robinson Seismic's advice and it's worked well for me.

[look 171]

Originally Posted by flatbutt

Brilliant! I'm getting ready to built a concrete pier for a large-ish telescope and will so do a concave hole.

Us boys seem to way over built, over analyze everything that has to do with fabricating something, large or small. Think about this for a bit, a simple 18"x18"x 24" deep footing or pad will hold up a huge beam that supports part of the second floor on a normal home. How big is this telescope? I understand its just a little more digging will create that concave hole. It isn't a big deal unless its the Hubble telescope but other then that, a simple pad will work jsut fine IMO.

[look 171]

Originally Posted by Bill Douglas

Yeah, it does make sense when you think about it. I've followed Robinson Seismic's advice and it's worked well for me.

Yep. Slows or stops the pad from creeping too.

[look 171]

SAT,

Here are a couple of pics of my deck, or should I say my kid's deck. They built about 60-70 % of it with me watching and doing some of the finish angle cuts and connection.

The beach chair is only 4' 3" wide. Its narrow. At 6', it becomes the walkway.

The pic with the angle deck and the tall glass window is a house I flipped up my street with all kinds of hill side foundation issues. We had to put in a new foundation on the entire side of the home. The "walkway" is 5' wide. Notice the old deck boards. I built the angle section so a table and a bit of outdoor living can be had for my new homers to enjoy the view. That section is about 12' in width going out from the house. There's an other section like it on the end of the house.

A couple more pic of the underside and the unfinished hand railing. Raw Ipe, needs lots of oil. My deck goes out from the house 14'.

[look 171]

Sorry, here's the flipped house. 5' isn't much

[Bill Douglas]

Stylish deck, Look 171.