Decks and Ramps Question

Gofor

Mark
Corporate Member
Building a 40' handicapped ramp for my BIL to use. It will have both an 8' x 8' landing at the door, and a 8' x 6' landing at about the halfway mark where i need to make a U-turn due to space limitations.

My question for you deck builders: What size hot-dipped galvanized through bolts do you use in the framing?. 1 bolt or two? On the web, I see 1/2" recommended, but thinking 3/8' would be more than sufficient especially if using 2 at each 4 x 4 . I am using 2 x 8s for the joists, but all will have support every 4' of run. Material is pressure treated pine. Another option would be 1/2" bolts for the headers and 3/8 for the side stringers.

As for load, the 8x8 deck may have up to four motorized wheel chairs (about 300lbs each plus 200+ lb occupant) at one time occasionally. On the ramps, (one chair/occupant in any location at a time) the 2 x 8 stringers will be on about 10" centers (4 stringers). Do you think 5/4 deck boards will be sufficient, or should I go with 2x lumber for the decking.
 

Sourwould

Taylor
User
Mark,

I'm a little confused as to what you're bolting to what.

Post to girder connections require 1/2" through bolts, if I recall correctly. When I was working in Asheville we always used 2 5/8" bolts per intersection. For laminating timber girders, I think just nails still flies. I would use the flatlok brand girder lamination structural screws to assemble the girder.

Wake county has a pretty good pamphet available online with guidance for girder span, 5/4 vs 2x decking, etc. Every answer you would ever want will be in the NC code Appendix M, which is available online. Most decks are designed for 40 pound per square of live load, 2500ish for an 8x8. I would overbuilt if I were planning to have 2000 lbs on it regularly.
 

Skymaster

Jack
Senior User
Your easiest,safest way is to contact the building inspector in the county you are going to build this in. Ramps,handicapped facilities have different codes, you don't want to have to tear it down, or have a po'd inspector gunning for you
 

Gofor

Mark
Corporate Member
I probably am not using the correct terminology. Post-to-girder connections are what I am talking about (basically, every place where the vertical 2 x 8 is laying against a 4 x 4 post). When I used the term "header", I was talking about the board that the cross joists are hanging from. For the joists that are not against a 4 x 4, I will be using galvanized joist hangers, fastened with six 1 1/2" 10d galvanized nails and four 3 1/4" 16d galvanized nails (diagonal) for each hanger.
 

Sourwould

Taylor
User
I probably am not using the correct terminology. Post-to-girder connections are what I am talking about (basically, every place where the vertical 2 x 8 is laying against a 4 x 4 post). When I used the term "header", I was talking about the board that the cross joists are hanging from. For the joists that are not against a 4 x 4, I will be using galvanized joist hangers, fastened with six 1 1/2" 10d galvanized nails and four 3 1/4" 16d galvanized nails (diagonal) for each hanger.
I would bump that 4x4 up to a 6x6 so you can set your girder onto the seat of a notch. Never built anything with 4x4s until I moved here, never liked stuff hanging on bolts.

Skymaster is 100% right though, check with your local building office.
 

Oka

Oka
Corporate Member
ADA Ramps typically are 1 in 12 rise -so 12 feet of ramp run = 1 foot rise or 30 inch rise = 30 feet of ramp run.

Turn in direction is 5'x5', Railing is 42" min and 34-38" high hand rand railing. Some cities want railing on both sides some do not care and only require 1 side.

Min loading is typically 40-50 lb per sq ft, you can use the 2nd floor joist/floor tables in the IBC as a reference go to the load span tables that have a heading of desired loading. Hope that helps
 

ScottM

Scott
Staff member
Corporate Member
Mark I am part of a community organization called Helpful Hands and Hearts that builds ramps for the needy. We have done over 150 in the 5 counties around where I live and everyone is different. Some of the places we build we double the property value by adding a 16' ramp. Some of the basics we use:
- Rise is 1" per foot. This is roughly 5 degrees.
- We use 2x6 for the joists and decking.
- Post are always 4x4.
- Width of the ramp should be no less than 36". Remember to account for any side rails and you will need side rails.
- We use 3 joists on a 36" to 42" wide ramp.
- It should be 36" from the decking to the top of the railing
- Use a 2x4 for the hand rail as a 2x6 is too wide
- One of the hardest parts is the transition at the end especially if ending on a hard surface like concrete or pavement.
 

Brian Patterson

Bstrom
User
If these ramps are going to get heavy just, I’d go up to 6X6’s for your posts - it’s code in my part of TN. Easier to work with when running bolts through them, etc.

There gobs of design and construction tutorials online for all manner of applications. Do the research and the job will go much better...
 

Gofor

Mark
Corporate Member
Thank you Scott. What you describe is exactly what I did 15 years ago when I put in a ramp for my MIL. The 2 x 6s were fine as they were laying directly on a concrete stoop giving great support. I did throw in the extra joist on the ramps due to my BIL using a motorized chair, and that ramp is still holding up fine. When I built the stoop along (with a steeper ramp as well as steps) for my shed, I used 3/8 bolts and they passed the Wayne county inspection with no problem. I am using the design you related, just stepping up the joists to 2 x 8s, but this one is not getting the material support from the church like my MIL's, and its in a different county, on my niece's land. Her hubby has the permits, but getting more info from that county's inspection dept has proven difficult at best. In this county, I have seen 3/8" through bolts, as well as 1/2" carriage bolts. I won't use carriage bolts because they have a tendency to spin in the treated pine, especially after a while, making it very difficult to tighten up the bolts after the wood dries and shrinks. Strength-wise, a solid shank 3/8 bolt is as strong as a 1/2" threaded carriage bolt, thus my question. I guess in retrospect I should have limited my query to just the bolt size.

I am well aware of the ADA guidelines, and am also aware that in many cases, they are a suggestion, not a requirement, for residential ramps, which this is. We are still trying to ascertain what applies for a residence in Pitt County.

I have watched the DIY videos ad nauseum, but realize most of these have a secondary purpose of getting you to buy expensive hardware when alternate and cheaper methods will suffice just as well for strength and utility. Fine when you are spending other people's money and you hand them the bill. Not so much so when its coming out of your own limited budget.

Thanks to all that replied.
 

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