How to Build Bunk Beds: Step-by-Step With Pics

Bunk beds are an awesome space-saving solution to pack more people into a smaller place. I have spent time in every possible bed in the past 40+ years.

And with no decent guides on the Internet I decided to use my 30+ years in construction to build the ultimate guide and share it with everyone.

How to build bunk beds weekend project by following these steps:

  1. measure the room
  2. create a plan
  3. determine budget
  4. create material list & purchase supplies
  5. build the top & bottom frame
  6. build and install the ladder
  7. install cross member joists
  8. install railing
  9. apply paint or stain

Update Jan 2, 2023: DIY build your own bunk beds book here at Amazon.

1. Measure the Height Area for Your Bunk Beds

Before you start designing your bunk bed (click for how tall on average) plans on a napkin you need to know how much space you have to work with.

If the bedroom is only ten feet wide you likely don’t want to build a King size bunk bed leaving only a narrow runway for a bureau and your legs.

Once you know there is ample space for the size bed you are building you can move onto the design stage.

2. How to Build Bunk Bed: Plan Options

Pick a basic bunk bed plan from below to determine how much the project will cost. You can modify the design with information in the following chapter using options such as logs, rails, and platform with logs cut with a chainsaw or table saw, bamboo, pallets, and more.

Obviously the cost to build the bunk beds is lower with the alternative free construction materials.

2.1 Make a Material List to Purchase

Use the tables below to create a material list for the bunk bed design that matches your napkin plans. It is time to go shopping at your local hardware store.

2.2 Table: Twin Bunk Bed Cost & Material List

These plans are designed for standard US Twin size and this one measures 39″ x 76″ to the outside of the frame.

This should provide an extra inch on for the width and length to make sure your mattresses fit in the bunk beds.

StructureMaterialCost*#Total
Cost
Cut
Length
Long frame boards
for 2 beds (joists 16″ OC)
2x4x8′$3.154$12.6076″
Short frame boards
for 2 beds
2x4x8′$3.156$18.9036″
Ladder rails2x3x8′$2.462$4.9278″***
Ladder rungs2x3x8′$2.461$2.467@12″
Ladder rung supports1x3x8′$1.682$3.3614@8.5″
Stats1x4x8′$1.9612$23.12
Wood screws for stats
2 packs of 100
1.75″$7.982$15.96
Joist hangers
(building code required)
4″$0.7512$9.00
Joist hanger nails
(building code required)
1.5″$18.9350 lb$18.93

Lumber prices for all tables courtesy of HomeDepot.

* Prices in USD and do not include sales tax.

2.3 Table: Total Bunk Bed Cost & Materials with Slat Platform

The table below is designed for two standard US Full-size mattress and this frame measures 54″ x 76″ to the outside of the frame.

This should provide an extra inch on for the width and length to make sure your mattresses fit in the bunk beds.

StructureMaterialCost*QuantityTotal
Cost
Cut
Length
Long frame boards
for 2 beds
2x4x8′$3.154$12.6076″
Short frame boards for
2 beds (joists 12′ OC)
2x4x10′$5.527$38.6451″
Ladder rails2x3x8′$2.462$4.9278″***
Ladder rungs2x3x8′$2.461$2.467@12″
Ladder rung supports1x3x8$1.682$3.3614@8.5″
Slats for 2 beds1x4x8′$1.9630**$58.8076″
Finish nails for fastening
ladder rungs to rails
3″$4.7550$4.75
Wood screws for frame4″$4.6975$4.69
Wood screws for stats
2 packs of 100
1.75″$7.982$15.96
Joist hangers
(building code required)
4″$0.7512$9.00
Joist hanger nails
(building code required)
1.5″$18.9350 lb$18.93

Lumber prices for all tables courtesy of Home Depot.

* Prices in USD and do not include sales tax.

** Quantity of slats is enough for no gaps so it is suitable for foam mattresses.

*** The length is up to you. The ladder can go to the ceiling or match the railing height.

Be safe when building bunk beds please!

2.4 Table: Queen Bunk Bed Cost & Material with Slat Platform

The table below is designed for two standard US Queen size mattresses and this frame measures 61″ x 80″ to the outside of the frame.

This should provide an extra inch on for the width and length to make sure your mattresses fit in the bunk beds.

StructureMaterialCost*QuantityTotal
Cost
Cut
Length
Long frame boards for
2 beds (one doubled)
2x4x8′$3.156$18.9080″
Short frame boards for
2 beds (joists 12′ OC)
2x4x10′$5.527$38.6458″
Ladder rails2x3x8′$2.462$4.9278″***
Ladder rungs2x3x8′$2.461$2.467@12″
Ladder rung supports1x3x8$1.682$3.3614@8.5″
Slats for 2 beds1x4x8′$1.9634**$66.6476″
Finish nails for fastening
ladder rungs to rails
3″$4.7550$4.75
Wood screws for frame4″$4.6975$4.69
Wood screws for stats
2 packs of 100
1.75″$7.982$15.96
Joist hangers
(building code required)
4″$0.7512$9.00
Joist hanger nails
(building code required)
1.5″$18.9350 lb$18.93

Lumber prices for all tables courtesy of Home Depot.

* Prices in USD and do not include sales tax.

** Quantity of slats is enough for no gaps so it is suitable for foam mattresses.

*** The length is up to you. The ladder can go to the ceiling or match the railing height.

2.5 Table: King Bunk Beds Cost & Material with Slat Platform

The table below is designed for two standard US King mattresses and this frame measures 76″ x 80″ to the outside of the frame. This should provide an extra inch on for the width and length to make sure your mattresses fit in the bunk beds.

StructureMaterialCost*QuantityTotal
Cost
Cut
Length
Long frame boards
for 2 beds
2x6x8′$6.514$26.0480″
Short frame boards
for 2 beds (joists 16′ OC)
2x6x8′$6.5112$78.1273″
Ladder rails2x3x8′$2.462$4.9278″***
Ladder rungs2x3x8′$2.461$2.467@12″
Ladder rung supports1x3x8$1.682$3.3614@8.5″
Slats for 2 beds1x4x8′$1.9634**$66.6476″
Finish nails for fastening
ladder rungs to rails
3″$4.7550$4.75
Wood screws for frame4″$4.6975$4.69
Wood screws for stats
2 packs of 100
1.75″$7.982$15.96
Joist hangers
(building code required)
4″$0.7512$9.00
Joist hanger nails
(building code required)
1.5″$18.9350 lb$18.93

Lumber prices for all tables courtesy of Home Depot.

* Prices in USD and do not include sales tax.

** Quantity of slats is enough for no gaps so it is suitable for foam mattresses.

*** The length is up to you. The ladder can go to the ceiling or match the railing height.

3. DIY Bunk Bed Frame Step by Step Guide

3.1 Set Up Work Area

Ideally, you have a garage with lots of room to work, and if you do then great!

If you are like most people I know you need snowshoes to walk through the garage and there is no chance that you are going to spend days cleaning out the crap and organizing the good stuff.

Ok, so where are you going to create a construction zone? How about outside? If you live in an area with good weather or have a covered deck this is a great option.

Keeping the mess and dust outside is much better than filling the house with an inch of wood dust.

You may want to do the construction in the bedroom if you live in a location where it can rain, snow, and be sunny every day eight months of the year like where I normally live in Nova Scotia.

TIP: Remove all items from the room and the closet to prevent wood dust infiltration into every possible orifice you can imagine.

This also gives you to work and swing lumber around without smashing lamps and photos.

TIP: If you are cutting wood inside the house you should turn off ducted heat and ventilation ductwork using vents and plastic and painter’s tape. Or anything that covers floor vents.

This extra coverage is to prevent the wood dust from getting into the face of the vent, which will blow into the room when the heat or AC turns on.

Or get sucked into the HVAC equipment for ventilation vents.

TIP: Purchase a cheap plastic sheet door with a zipper and tape to the bedroom doors. Doors have a gap at the bottom and this allows wood dust and paint fumes to enter the rest of the house.

Use two workbenches to make cutting the lumber much easier than bending over to the floor for each cut.

TIP: If you don’t have workbenches you can use a couple of kitchen chairs facing away from each other. The ideal chairs have handles sticking up a few inches on each side to keep the lumber from sliding off.

TIP: Confirm using the chairs is OK with your spouse first or you may get yourself into a pile of poo.

TIP: Open the windows and use a fan to help blow the wood dust out of the bedroom and onto your neighbor’s freshly washed laundry hanging on the clothesline.

Gather up all the tools that you think that you will need and put them in the bedroom.

This will reduce the number of times you have to expose the rest of the house to the construction dust you are going to create in the bedroom.

Tools you need include:

TIP: If you do not have a three or four-foot level you can simply measure from the floor and mark the measurements on the wall. The floor should be level and you are not building a piano.

TIP: If you don’t have a square you can simply cut a piece of lumber at least 12” long and place it against the lumber you want to cut.

Make it with the factory edge of the lumber on the line that you marked on the lumber to cut.

Use the pencil to mark the line across the lumber to cut. This provides a 90-degree square mark.

TIP: If you do not have a stud finder you can find the studs by removing the plate cover off an electrical outlet using a flat screwdriver.

Turn the electrical breaker off if you are not comfortable around electricity. Use a flashlight to see which side of the electrical box the stud is located.

If you can’t see the wood stud you should be able to see which side of the box has the screws which fasten the box to the wood stud.

Measure 16.75”, 32.75”, 48.75”, 60.75”, and so on until you hit the other wall) from the drywall on the side where the stud is and make marks with a pencil.

WARNING: If you need to measure from the stud side of the electrical box across the box the measurements are different and they are 15.25”. 31,25”, 47.25”, and 59.25” and so on as needed.

3.2 Cut Bed Frame Lumber

Use your circular saw, table saw, radial arm saw, reciprocating saw, or hand saw, to cut lumber and slats to the lengths listed in the table below.

TIP: Do all the cutting at once to allow the room to clear of wood dust for the remainder of the construction.

If you cut each piece of lumber as you need it you will spend the day snorting wood dust while half-blinded by the never relenting dust storm you are creating.

3.3 Install Joist Hangers

An easy way to install the joist hangers (like these) is to do it before building the wood frame. Following these steps:

  1. Place the four long 2x4s on the floor, face down, with one end pushed against a wall to keep them flush with each other.
  2. Measure from one end of the 2x4s and mark the measurement and draw an X of the opposite side you are measuring from for all four. This indicates which side of the line the cross member (joist) is to be installed. Mark 16”, 32”, 48”, and 64”.

    DO NOT MIX up the direction of the boards or the joist hangers won’t line up.
  3. Nail the joist hangers ON THE MARK SIDE ONLY on the X side of your marks using the joist hanger nails. The joist hangers and N10 hanger nails are required by most building codes in Canada and I am sure in the USA too.

TIP: Nail the other side of the joist hangers after you install the cross member joists as this is much easier. Or you can do it like in the video below.

3.4 Install Bed Frame Rails On Wall

Convince someone to help you with this task as holding a long 2×4 against the wall while level and trying to get a screw started is not a good idea for newbie carpenters. Then follow these steps:

  1. Measure up from the floor 62” and make a mark on the wall.
  2. Use a three or four-foot level to continue the mark where the bed shall be. If you don’t have a large level you can simply make two measurements, one near each end.
  3. Ask you less than enthused apprentice to hold one end of a long 2×4 and hold it against the perpendicular wall with the bottom of the 2×4 on the mark.
  4. You hold your end with the bottom of the 2×4 on the mark and drive a 4” screw through the 2×4 and into the drywall and wall stud.
  5. Got to your apprentice’s end and drive a screw to relive him or her of her burden.
  6. Do the same for the short 2×4 frame lumber on the perpendicular wall.
  7. Use one of the remaining long 2x4s to create a temporary brace for the two remaining frame members.
  8. Ask your apprentice to hold up the end of the lumber that is opposite the wall it is attaching to.
  9. You hold the other end against the short 2×4 mounted on the wall and drive a 4” screw through this lumber and into the end of the short 2×4 that is already mounted on the wall.
  10. Hold the temporary brace against the rail and use a level to determine the position to mount the lumber on the brace. If you don’t have a level you can simply measure and mark the temporary brace.
  11. Ask your apprentice to continue holding as the 2×4 can easily fall over and knock you on the head.
  12. Set the short last short 2×4 for this bed frame into the two joist hangers and hold it in place while you attach the end near your apprentice.
  13. Drive four 4” screws into the face of the long 2×4 the apprentice is holding 0.74” from the end and into the short 2×4. Make sure not to move the temporary brace as one end of the short rail is only sitting on the 1.5” ledge in the joist hanger.
  14. Finish installing the remaining screws in the two bed rails installed against the wall with four 4” screws in every stud. Make sure you hit the studs for strength and you will be able to feel when you miss a stud.
  15. Place the remaining cross member joists into the hangers and wrap the hanger around the lumber and nail to the rail and the joists to join it all together.
  16. Repeat this process for the bottom bunk.

TIP: If you are right-handed you want to be on the left side of the 2×4 and your partner on the right. And the opposite is true for us left-handers. Why? Image holding the end of the 2×4 with your left hand. So the lumber is to the left of your body.

Now you have to reach across your body and try to drive a screw with the back of the drill in your face.

Of course, a simple fix is to hold the lumber in from the end so that your drill hand can easily access the lumber where there is a stud.

3.5 Build and Install Bunk Bed Ladder

DIY bunk bed (costs and weights average here) ladder is constructed with 2″ x 3″ lumber cut 78”-84” for the rails and 12” for the rungs. 1″ x 3″ x 8.5” lumber is attached to the rails to support the rungs. The ladder provides support to lower and top bed frames by providing two posts sitting on the floor and attached to the rails.

5.1 Determine the Height of Ladder Rungs for Bunk Beds

The gap between the ladder rugs must be a minimum of 10″ (Source: OSHA). Therefore the height of ladder rungs for bunk beds, to the top of the rung, are:

  • 10″
  • 20″
  • 30″
  • 40″
  • 50″
  • 60″
  • 70″

5.2 Width of Your Ladder Rungs

The width of the ladder rungs for bunk beds (fixed ladder) must be a minimum of 12″ between the rails (Source: OSHA)

5.3 Follow these Steps to Build Bunk Bed Ladder

  1. Cut two 2x3x8′ boards to 78″.
  2. Attach one 2x3x8′ on edge to the side of the top bunk 2×4 frame 1.5 inches from the corner on the foot end of the bed. (DIAGRAM).
    1. place the bottom of the 2×3 on the floor near the corner of the bed.
    2. From the inside of the bed frame hold the rail in place with one hand and drive a 4″ wood screw through the bed frame into the ladder rail.
    3. Check the position of the rail on the floor and tap into place using a hammer and a woodblock (the woodblock prevents round hammer indents in the ladder rail).
    4. From inside the bed frame drive one 4″ screw through the bottom bed frame into the ladder rail.
    5. Confirm the ladder rail is in the correct location and plumb (not leaning like the Tower of Piza).
    6. Measure from the inside of the ladder rail and mark 12″ on top of the bottom bed frame rail.
    7. Do the same for the top bunk frame, but unless you are “The Mountain” tall mark the bottom of the top rail.
    8. Lean the second ladder rail against the bed frame and go into the frame.
    9. Hold the 2×3 rail in position (making sure the lumber is on the correct side of your mark) and drive a 4″ wood screws through the frame and into the ladder rail.
    10. Repeat for the bottom.
    11. Check measurements to confirm 12″ between the ladder rails at the top and the bottom.
    12. Drive three more 4″ screws in each the top and bottom bed frame into the ladder rails.
  3. Cut 14 pieces of 1×3 lumber at 8.5 inches long.
  4. Cut 7 pieces of 1×3 lumber at 12″ long.
  5. Attach one 1x3x8.5″ to each ladder rail starting flush with the floor. You can attach them using:
  • glue so there are no exposed fasteners in the finished product. Spacers can be cut to hold the wood in place until the glue dries.
  • 2″ wood screws starting on the rail side and then fastening the 1×3. If you go through the 1×3 first the wood will split. Wood putty or plugs can cover the fastener heads.
  • brad nailer or micro pinner to drive finish nails.
  • hammer and finish nails. Old-school works just fine!
  1. Place a 2x3x12″ on the top of the 1x3x8.5″ and confirm it is level using a torpedo level (a small level).
  2. Fasten the ladder rungs to the rails using one of the methods listed above.
  3. Repeat the process for the seven rungs.
Bunk bed ladder

3.6 Install Platform Slats

Add the slats to the top bed frame starting at either end. It should work out that you won’t need to cut the last slat to width if you allow a small gap in some of the stats to finish with a full slat. Fasten the slats with two 1.75” screws or two-inch nails on each end.

I prefer screws because they hold better and can be removed if the bunk needs to be removed in the future.

Repeat for the bottom bunk.

3.8 Paint or Stain Bed Frame

It is time for paint or stain because it is easier to paint the frame without the railing in the way. Use a paintbrush or roller for paint and a brush or cloth for stain.

Use wood putty to cover the four screws exposed (eight total) in the rails at the one corner. These will disappear under paint or blend in with stain.

If you want to add character and a rustic look to the frame you can very carefully use a propane torch to make burn marks in the lumber price to staining.

3.9 How to Install the Railing

How to Install Railing Using Wood Boards

Wood boards such as pine or spruce-pine-fir in widths of 2”, 3”, and 4” can provide a strong and sturdy railing while providing more privacy than railings with thin posts. To build this type of railing follow these steps:

  1. Cut the 16” long.
  2. Nail or screw them to the bed frame flush with the bottom of the 2×4 starting at the ladder rails and work towards the walls.
  3. Leave a space up to 3” between each board depending on your preference for looks and privacy.
  4. Nail or screw a handrail on top using 1×3 or 2×3 lumber or pine boards.
  5. Fasten the handrails to the ladder rails.
  6. Apply paint or stain.

How to Install Wood Ballasters/Wood Spindles

Same as above, just a different look with less privacy. Check out the options at your local hardware store.

Some hardware stores sell prebuild handrails that just need to be cut to length and the wood spindles fit into pre-cut holes to make your life much easier.

How to Install Aluminum Posts

  1. You can use aluminum railings for decks and cut to length using a hack saw or grinder at 15” high.
  2. Measure and mark 3.15 inches on top of the bed frame starting at each rail of the ladder and work towards the walls.
  3. Use a wood spade bit 1?/16th of an inch larger than the diameter of the aluminum poles to drill holes in the slats and 1” into the top of the bed frame around the perimeter.
  4. Measure between each ladder rung and the two walls and cut two 2x3s for the top handrail.
  5. Mark each every 3.25” starting from the ends that will be installed against the ladder rungs.
  6. Use the same wood spade bit to drill holes 1” deep.
  7. Insert the aluminum poles into the holes drilled into the bed frame.
  8. Paint or stain the 2×3 handrails to match.
  9. Slip the handrails over the aluminum poles starting at one end and working across to the other end.
  10. Fasten the ends against the ladder rails with screws on a diagonal.

TIP: You can cut the thin aluminum poles with a circular saw or table saw with the blade turned backward. Just go slow. I had a gutter (eavestrough business) and this method worked perfectly for cutting aluminum gutters every day.

3.10 How to Paint or Stain Ladder and Railing

Apply paint or stain to the ladder and consider adding anti-slip stickers or paint to the ladder top of the rungs, not the commercial ones that are designed for work boots, not bare feet.

You could also paint the lumber prior to installing to make it easier to reach all areas.

3.11 How to Install Mattress, Then Enjoy

Install the mattress from the foot end of the bed. If the bedroom is not long enough you can stand the mattress against the foot of the bed, lift the bottom as far from the bunk bed as possible and bed it as needed to pop it into place.

Additional Helpful Information

How Much Does it Cost to Build Bunk Beds

For simply lumber construction the costs to build bunk beds are $113.94 for twins, $174.11 for full-sized, $188.25 for a queen, and $234.87 for a king. This is based on 2×4 construction all but the king, which is 2×6 construction

How High is a Top Bunk Bed?

The top bunk is 66″ to 72″ to the top of the bed frame to allow enough space between the mattress and the ceiling for bedrooms with a standard eight-foot ceiling. Top bunk bed maximum height is calculated for other ceiling heights by subtracting 24″ from the ceiling height.

It is more comfortable if space allows more height between the bed frame and the ceiling.

More space also allows for more mattress options such as tall mattresses with pillow-top options.

Table . Top Bunk Bed Total Head Space Clearance

Bed
Height
Mattress
Height
Floor –
Ceiling
Head
Clearance
66″6″96″24″
66″7″96″23″
66″8″96″22″
66″9″96″21″
66″10″96″20″
72″6″96″18″
72″7″96″17″
72″8″96″16″
72″9″96″15″
72″10″96″14″

How Much Space Should be Between Top and Bottom Bunk?

The space between the top and bottom bunk should be a maximum of 56”. This is for bedrooms with a 96” ceiling, and bed frames 4” high, and the top of the bottom bunk 12” off of the floor, and top of upper frame 72” from the floor. This provides 24” space for the top bunk and bottom bunk has 56”.

How Much Space Between Triple Bunk Beds

The space between triple bunk beds is between 24” and 28”. If the first of the triple bunk beds frame top height is 12” off of the floor and the top of the middle frame is 44” off the floor that provides 28” of clearance for the bottom two bunk beds.

Lower the top two bunks 2” for 26” space for each.

To be more fair to the third top bunk the construction of the second frame could be lowered by two inches and the top bunk by two inches.

That would give each of the bunk residents 26 inches of vertical space.

That may not sound like a big increase for the penthouse, but it is an 8.3% increase in valuable real estate.

How Tall is a Triple Bunk Bed?

A triple bunk bed is 72” tall to the top of the top frame. This is 24” below the ceiling height as most ceilings in the USA and Canada are 96”. If the mattress is flush with the top of the upper bunk frame there is 24” clearance to the ceiling. A mattress on top of the frame has less clearance.

Table . How Much Space Between Top Bunk and Ceiling Chart

Ceiling
Height
Bed
Height
Frame
Thickness
Mattress
Thickness
Mattress
in/on
Frame
Mattress
– Ceiling
96”72”4”4”On20”
96”72”4”4”In24”
96”72”4”6”On18”
96”72”4”6”In22”
96”72”4”8”On16”
96”72”4”8”In20”
96”72”6”4”On20”
96”72”6”4”In24”
96”72”6”6”On18”
96”72”6”6”In24”
96”72”6”8”On16”
96”72”6”8”In22”

Are Bunk Beds Twin or Full?

Most children have bunk beds that are twin or full, but all sizes have applications including:

  • Queen and King for Airbnb rentals to increase rent potential.
  • Queen and King for wilderness communal camps for hikers, hunters, and adventurers.
  • Queen and King for personal cottage and camps to accommodate my weekend visitors.
  • Any size works for part-time boarders such as in and out workers. Workers would greatly appreciate having their own bed each time they return and if enough beds in a room this can work out.

What is The Average Length of a Bunk Bed?

The average length of a bunk bed is 77″ for twin and full size and 82″ for twin XL, queen, and king including the railing. Some models have stairs at the end of the beds which increases the length by an average of 16″

What Size Lumber for Bunk Beds

2×4 lumber is adequate size lumber for bunk beds rails and joists for twin and full-size beds, 2×6 lumber for a queen, king, and California king size. 2×4 lumber can be used for building platform joists (16” OC for twin and full and 12” OC for queen and king). 1×4 for the slats and 2×3 for railings.

Which Wood is Best for Bunk Beds?

Spruce-Pine-Fir (SPF) dimensional lumber is the easiest to work with and a low-cost option that is available at all hardware stores. This is the lumber home builders use and it certainly works for bunk beds.

Other options include logs, pine or hardwood boards, and even pallets for the foundation.

Can You Put a Regular Mattress on a Bunk Bed?

Any regular mattress works on a bunk bed if the platform slats gaps are under 2″ or it has plywood for a platform base for the mattress to lay on. Most bunk beds designed for use in the USA and Canada accept the standard mattress sizes for twin (38×75), full (53×75), queen (60×80), and King (76×80).

What Size Mattress Fits a Bunk Bed?

Mattresses that fit bunk beds are the same as regular beds when designed for the USA and Canada. These sizes include:

  • Twin: 38″ – 39″ x 75″
  • Full: 53″ x 75″
  • Queen: 60″ x 80″
  • King: 76″ x 80″

Is a 6-Inch Mattress Thick Enough?

A 6-inch mattress is thick enough for children, teenagers, and adults up to 200 lb if it has good support. such as a good quality foam mattress. A 6-inch mattress is common in travel trailers, RVs, bunk beds, boats, and cottages. Millions of people in Asia sleep comfortably on a 4-inch mattress.

It might help you out to scan my article about how to build a bed frame here.