Construction Design

When designing your ipe deck, you should keep several things in mind. First of all, check your local building codes, then follow these general guidelines:

Porch vs. Deck

For our purposes, a porch is covered, a deck is not. If you’re building using tongue & groove boards, they must be installed in a covered environment. With no gap between the boards, a tongue & groove porch must be installed with a slant to allow water to drain away.

Joist Spacing

Here are some guidelines for joist spacing in an ipe deck. These numbers are conservative, and compliant with most building codes. They are also good for when the boards are arranged diagonally.

Deck Board – Joist Spacing

  • 1×4 – 16″
  • 1×6 – 16″
  • 5/4×6 – 24″
  • 2×6 – 32″

Board Spacing

Because all wood naturally expands and contracts with changes in the climate, you should allow for it by leaving some space between the boards. Ipe generally only expands side-to-side, not length-wise. If you’re installing your ipe deck in a warm, dry climate, we suggest a 1/16″ gap. For a cold or wet climate, we suggest a 1/8″ gap.

Without this spacing, your ipe deck can buckle as the wood expands.

Ventilation

Proper ventilation is vital. If water gets underneath the deck, the underside of the boards will stay wet, but the topside will dry and shrink, causing the boards to cup.

To prevent this unsightly cupping, install your ipe deck at least 12″ off the ground and allow for good air flow underneath.

Installing hardwood decking above a concrete pad is NOT recommended. Hardwood decking should never be installed directly over concrete due to moisture retention. Any hardwood decking installed over a new or aged concrete pad will cause the deck boards to cup and/or crown.

Comments

robert shawkey

February 4, 2011

What is the distance recomended for the screws from the side of the board? As far as a 1×6.

    jcolton

    July 12, 2011

    I would suggest a minimum of 1/2″.

Pat Radle

January 5, 2013

I am writing on behalf of our condominium association. Last week, our local fire inspector (Milwaukee, WI) notified us that grills could not be used within 10 ft of combustible materials, including the balconies. I did some research to find that Chicago building codes are allowing Ipe decking, and Chicago has strict fire laws. So if Chicago allows it, I’m guessing that Milwaukee will as well.
Each of our balconies has a suspended steel frame 8′ wide extending 5′ from the brick building exterior wall. The steel frame has steel “joists” every 2′, perpendicular to the building. The existing decking is very simple and is basically ten 2 x 6’s, 8′ long dropped into the steel frame. So there is excellent ventilation under each deck.
I am trying to figure out if 5/4 x 6 Ipe will have a similar strength. If so, I would try to price out the material. We have 45 balconies.
Thanks
Pat

    Ipe Deck Builder

    January 7, 2013

    With regard to the fire code, make sure you check with your actual local regulations, just to make sure.

    2′ spacing between joists is exactly what’s recommended for 5/4×6 ipe, so you should be fine there.

    FG

    July 24, 2013

    Chicago allows rooftop decks to be ipe, but the city still frowns upon open flame, i.e. charcoal grills on decks or porches. Gas grills are allowed on steel decked porches and balconies, but not wood, which is why there is confusion about this item. I’m sure neither charcoal or gas grills would be allowed on decks where ipe would be used as a fire-resisting solution.

Shawn

January 24, 2013

I am bidding a project that calls out IPE for virtical siding panels. 6 x 5/4 with 1/4″ gap between each board, what should my sub girt spacing be for this application?

    Ipe Deck Builder

    January 25, 2013

    I’ve seen spacing anywhere between 24″ and 48″. What you need to do is see what the local building code requires based off the load and design.

tonya

March 6, 2013

I have a very large Ipe deck with hidden fasteners. We have bad cupping in a few boards in critical areas. The deck is floating 18″ above grade, we are near the water so there is a lot of moisture. Due to the install with hidden fastners removing the cupped boards is not an option. Do you have any suggestions on how to fix I was considering using and sander for wood floors to even out and sealing? We have not sealed the deck yet.

Thanks

Robert Shuler

May 3, 2013

We have a situation where we want to install 5/4 x 4″ Ipe over existing concrete pad (removal of pad is not an option)..using PT 2×4 sleepers. Is there anything we can do to mitigated the risk of cupping?
Thanks,

Robert

    Ipe Deck Builder

    May 6, 2013

    Using thicker, narrower boards like 5/4×4 will help. You want to get as much air flow beneath the deck boards as possible; the recommended minimum distance is 12″ of space beneath the deck. Regardless, I don’t recommend installing plank decking of any kind over concrete, because no matter what you do it is most likely going to cup and buckle. Alternatively, you could use decking tiles, which are designed to be installed over concrete slabs: http://www.advantagelumber.com/decking-tiles/

Tim

May 4, 2013

I am installing an ipe deck, and I am wondering about two things. One is whether you have any experience or opinion about using the Camo hidden fastener system of Tigerclaw hidden fastener system with ipe, and if so if there is a maximum width of board you would recommend using it with–only up to 4″wide or up to 6″ wide?

Also, I have read several places to treat the deck before installing and then treat again in a few months. Do you recommend this? And regardless, would you sand the boards before treating, for example with penofin, or is it better not to sand before treating?

Thanks so much. There seems to be so much conflicting information out there!

    Ipe Deck Builder

    May 6, 2013

    I don’t have any experience with the Camo system. I do, however, have experience with the Ipe Clip brand of hidden fasteners, and they can be used on any size of decking.

    I recommend applying the oil finish to the decking after it has been acclimated to the job site, then again 6-8 months later. After that, you only need to treat the deck every other year.

    You don’t need to sand the deck, but if you decide to do it anyway, you should pressure wash the deck before applying any finish to make sure no debris gets clogged in the pores of the wood.

Eric

August 2, 2013

When you say the deck should be a minimum of 12″ off the ground, are you referring to the decking or the bottom of the joists? I am trying to get the deck as close to the ground as possible since the ground is only 12″ below the doorframe.

    Ipe Deck Builder

    August 2, 2013

    That’s 12″ from the joists.

Tim

October 10, 2013

I have a 27’x7′ covered front porch with 2×8 pt joists 4″ off the ground. Is there a way to use 4″ wide ipe screwed and plugged in this application without it cupping. Would I need more ventilation?

    Ipe Deck Builder

    October 10, 2013

    Using thicker material (5/4×4 as opposed to 1×4) will help minimize cupping. Of course I’d always recommend getting in as much ventilation as possible. Another option would be to use wood deck tiles, since those were designed to work in low-ventilation applications.

Sibyl

January 27, 2014

Ipe decking over Trex steel framing has a noise component to it like walking on bleachers. Hard sole and heel shoes are very noticeable vibratory sounds. Any recommendations for dampening the sound? A portion of the deck has been built revealing this annoying problem. Holding off on completion if some sort of padding between ipe and steel can solve the problem.

Edward Thomas

May 18, 2014

Installing approx. 3,000 sf in New Jersey what would the recommended spacing be? Where the decking meets on joist should we straight cut, or 45 degree?
Thanks,
Ed

    Ipe Deck Builder

    May 19, 2014

    If you’re installing your ipe deck in a warm, dry climate, we suggest a 1/16″ gap. For a cold or wet climate, we suggest a 1/8″ gap.

    Straight cuts are fine.

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