Introduction: $14 Secret Crawlspace Access Door

Picture of  $14 Secret Crawlspace Access Door

This is a hidden crawlspace access door that I built into my bedroom closet floor. It allows my crawlspace to now serve as a storm shelter, a safe room(a place for my family to hide in case of an intruder), and a storage area.

I built it 2-3 years ago and it has been opened and closed 100's of times with no signs of wear and tear. The door is so well hidden that even I cannot see it when it's closed, and I know exactly where it is. There is no handle needed, you simply pull on the carpet to lift the door.

The scariest part of taking on a project such as this is cutting through a perfectly good floor. Who wants to be the guy who screwed that up, right? In steps 1 & 2 I explain a full proof method for marking & cutting the door opening precisely & accurately.


Piano Hinge @ $6

Barrel Bolt latch/lock @ $3

Double Sided Carpet Tape @ $5

Rubber door seal @ optional

Handle for underside @ optional

permanent ladder @ optional

scrap 2x4 @ free

Tools Required

Box knife

circular saw

reciprocating saw


1/8" or smaller drill bit

(2) squares

tape measure

5 BBQ skewer


duct tape

Step 1: Mark Opening

Picture of Mark Opening

1) You need to find a suitable area you would like your secret door to be located. (Your floor joists will ultimately determine precisely where the door can be located)

2) Once you have found a suitable location, drill a very small hole through your floor.(1/8" or smaller) This hole should be roughly in the center of your door location. Slide your BBQ skewer 4-5 inches into the hole and secure it. If the skewer does not slide through completely, you may have hit a floor joist. Drill another hole 2" away and try again. Warning! Do not allow the carpet to twist around your drill bit. Don't worry about the hole, the carpet will hide it. Trust me; if you pull out the skewer, you may never find the hole again.

3) Go into the crawlspace and find the skewer. Now that you know which floor joists your secret door will be located between, drill 4 holes up through the subfloor.

- Measure out 1 1/2 inches from the joist and drill a hole up through the subfloor and carpet. Drill a 2nd hole 1 1/2 inches away from the same floor joist 10 inches away from the first. Both of these holes should be inside the area of your access door location.

Repeat this process with the opposite floor joist.

Now slide a skewer into each hole and duct tape it into place.

4) Head back upstairs and place the fat(2") side of your square along the outside edge of 2 of the skewers (parallel to your floor joists). The 2" side of your square will overlap 1/2" with your floor joists. Do the same with your other square and skewers. If you measured correctly, your squares should form a perfect rectangle. You can adjust the length of your door to your needs, but the width is predetermined by the spacing between your floor joists.

Step 2: Cut Opening

1) It is time to cut out your opening. Using your sharp box knife, cut the carpet and padding along the outside edge of your square, leaving the carpet on the hinge side of your door intact. Only cut 3 sides! Do not rush through this step or your door may be visible after completion. Take your time and be precise.

2) Fold the carpet and padding back and cut all 4 sides of your subfloor using your circular and reciprocating saw. (the carpet will hide any imperfections in your subfloor cuts)

3) You should now be able to pull the door out of your floor completely. If not, your subfloor may be glued in place. If this is the case you will need to go back into the crawlspace, slice between the subfloor and joists with your box knife and pry it up with a crow bar.

Step 3: Prepare Opening and Door

Picture of Prepare Opening and Door

Your door should already be the perfect size for the opening. Now you can install the 2x4 cross braces, the piano hinge, locking barrel bolt, handle(optional), and rubber seal(optional).

1) Add a 2x4 support between the floor joists at each end of your door opening. It should only extend 1/2 inch into the door opening to support the door when it is closed.

2) If you are going to install an adhesive rubber door seal, a recess needs to be cut around the underside perimeter of your door to account for the extra thickness. install the seal on your floor joists, put the door into place, and measure the difference in height to find your recess depth.

2) Install hinge. The hinge needs to be recessed so there is no visible bulge in your carpet. Line up your door in the opening and put the hinge in place, mark the outline onto the door and subfloor. Use a chisel or router to cut a recess for your hinge. reposition your door and attach the hinge. (I used a gate style hinge, but a piano hinge will be much easier and just as strong) Make sure the door is aligned with the opening properly.

4) Install barrel bolt lock and handle. Drill a hole into the side of your floor joist to accept the barrel bolt.

Step 4: Attach Carpet

Picture of Attach Carpet

1) The carpet around the perimeter of the door opening needs to be secured to the subfloor. First apply double sided carpet tape to the subfloor on all sides of the door except the hinge side. Secure the padding to this tape. Then apply tape to the top of the carpet padding in the same areas and secure the carpet to this tape.

2) The padding and carpet need to be secured to the secret door. Only apply carpet tape to the side of the door opposite the hinge. This will allow the carpet and padding to flex when the door is opened. Since I pull on the carpet to open the secret door, I decided to also use wood screws every 4 inches to secure the carpet to this side of the door. Do not screw them in too far, you don't want suck the carpet down and leave a visible indention.

3) Clean up the edge of your carpet and padding with your box knife so the door closes easily.

I installed a permanent ladder and light switch to make the space more accessible and useable.


jack-ee (author)2015-02-02

Your crawl space is much larger than mine and mine has a dirt floor. It is only 2 cinder blocks high in the back of the house and 3 in the front. I'd love to do this to hide valuables, etc. Just wouldn't know how to keep moisture away from what I would place down there. Any suggestions?

smashing (author)jack-ee2015-02-02

I'd forget the steps and make or buy a plastic bin that you could hang in the hole.

jack-ee (author)smashing2015-02-02

That's a good idea! Although it wouldn't solve the moisture issue. I guess I could vacum seal.

smashing (author)jack-ee2015-02-02

Sure it would. The plastic tub is waterproof by nature. Secure it with screws or nails and seal edges with silicone. Unless you're talking about from above then you would just have to use the matching cover or invent one of your own

gumby_kevbo (author)smashing2017-12-13

Unless the tub seals like a tupperware container, it will breath with diurnal changes in barometric pressure. In many climates this will result in significant condensation inside. Ziplock bags are better, because with soft flexible walls, they are not as prone to breathing as a rigid container.

haughpf (author)jack-ee2016-04-14

If your crawl space wasn't so small, I'd recommend encapsulating your crawl space in regards to the moisture. Though it might still be a good idea so that you do not get mold and rotting floor joists.

goldamazon (author)jack-ee2015-02-06

Jack-ee if I was you I would look into purchasing old metal ammo boxes from an army surplus store. They have a gasket to prevent the ammo from getting wet or corroded and are made for military use so you know they are tough. Add some silica gel or another type of desiccant in the box and that is what I would do to keep stuff dry and vermin free.

super_me (author)jack-ee2016-08-22

you could use a small dehumidifier

Ilovelamp (author)jack-ee2015-02-02

If you want to hide smaller items, then check out my secret drawer lock:
It can be added to an existing dresser, nightstand, etc... And would be easier than building the secret crawl space door.

My crawl space is not vented, the exterior walls are insulated, the ground is gravel with plastic, and I installed a back up sump pump. So I don't have moisture issues. You definately don't want to ruin your valuables by sticking them in a crawl space with high humidity or that is prone to flooding issues.

jack-ee (author)Ilovelamp2015-02-02

Thank you I sure will check it out!

bcavaciuti (author)jack-ee2015-02-03

If you do want it less susceptible to brute force like the night stand, which will stop a quiet thief but not a sledge!

With every lock, once the owner is threatened they are defunct and more useful to a thief because all the valuables are in one spot. That is why concealment works best because if the thief don't know he wont ask. For moisture control, try just wrapping everything in multiple plastic bags, inside a bin or waterproof sack:

Always works when camping...just don't use biodegradable bags!

mollisgu (author)2016-03-07

could come to someones house and make it for them

mcfunworld (author)2015-07-17

could I do this on wood floor

mcfunworld (author)mcfunworld2015-08-06

and can you post pics of b underneath the house (in the crawl space)

alisterdark (author)2015-01-31

It varies by state, but in my state, this wouldn't be up to code, you'd need to replace the 2x4s with at least 2x8s to run between the joists to box it out. Be sure to use pressure treated wood, and galvanized nails for a project like this, as anything else is prone to rot.

Just my $.02, but if you ever want to sell your home, always have it up to code.

singalls (author)alisterdark2015-03-09

Seeing as how I found some items in my house after it was bought that were not up to code, I have to agree with you on this one. Its always best to be up to code. Codes were made for a reason after all.

diy_bloke (author)singalls2015-06-14

I agree "codes were made for a reason after all", but it doesnt always have to be a good reason :-)
Where I live, if you want to make a fawcett on the front of yr house, the attachment plate (not the entire fawcet) needs to be recessed in a metal bowl. For what? god knows. No other country has that and still there are no major disasters around fawcets in surrounding countries. Then ofcourse there is the european rule of a maximum height for doors. A minimum height i can understand, but a maximum?

I concur. If you're going to do something like that, do it right.

Didn't see joist hangers either.

brainiac5 (author)alisterdark2015-02-01

Very cool, however Fire fighters and rescue squads hate hidden rooms, it is difficult to find survivors/victims and there could be danger from collapse in the event of a fire or other catastrophe.

shizumadrive (author)brainiac52015-02-01

Firemen are against almost everything. No candles, no lighters, no fireworks. Toaster should be unplugged when not in use. Some I've met seem to want people to sit in a room with no appliances and sit there and do nothing when you are at home.

I know they have horror stories and live a dangerous life but they need to not worry that everything possibly bad will happen.

jack-ee (author)shizumadrive2015-02-02

I worked in EMS based out of a Fire Dept. I never met any like that.

jack-ee (author)brainiac52015-02-02

They also hate ppl who store stuff in the attic.

alisterdark (author)2015-02-01

I wasn't being overly critical. Just trying to keep folks on the safe side of construction. Offering my advice as a former contractor. No need for anybody to get snippy, this is a website built around projects, constructive criticism and knowledge sharing. That's all I was doin', fella.

laurabar (author)alisterdark2015-02-01

There will always be one jealous soul out there to swipe at others. Forgive and forget was created just for them.

Mark620 (author)laurabar2015-02-21

That's till they use it against you.

Every contractor I've worked with in the last thirty years has been a lazy do-nothing crook who cuts every corner possible to make a buck at the expense of the homeowners that hired them.

I'd sooner take advice from a used car salesman.

oneromanticgirl (author)2015-02-01

I love this! We were hit by a tornado in 2013 and had nowhere to go but an interior room, which missed us by inches. I miss having a basement and would love access to my crawl space in times like that. Thank you!

hmmm, i'd just make sure there is an exterior door.....would not be cool if your house collapsed on the trap door, trapping you inside!

mccoolll (author)three_jeeps2015-02-09

I keep a crowbar in my crawl space for just that reason.

Excellent point!!

Kathy68 (author)2015-02-02

I love the idea. In Australia it would add value to your home if you were to sell. Although if you built one you wouldn't let everyone know except those you fully trusted. You certainly wouldn't go through your local greedy council here in Oz who would want plans & for you to pay them to have it approved or not. Keep up the gr8 work :-)

smashing (author)2015-02-02

Good post but it looks like the door would be better opening the other way. Maybe not - just how it looks in the pics. Something to keep in mind for anyone doing this.

PrestonW1 (author)2015-02-02

this would be a cool idea i want to make it in my room does it work only in bottom floors or can i do it on the main if there is a basemen?????

r0668018 (author)2015-02-01

some of you peoples comments are over the top. its his house, he can do what he wants! legality? hmmm, lets vs building code, thats a no brainer, even for you critics. try and be safe with the building code book over your head. if small children are a concern... put something heavy over it. common sense isnt common.

jack-ee (author)r06680182015-02-02

I was thinking the same thing. I live in rural Oklahoma and don't have to worry about asking permission to build something on my own property or for something like this.

lionel1024 (author)r06680182015-02-02

Building code vs safety? Building codes are generally for safety reasons.

Ilovelamp (author)2015-02-02

Thank you all for your comments and suggestions. If your worried about not being able to sell your house because of this, it would be very easy to seal the door to bring it back up to code.
If your concern is safety, I can assure you that there are many other hazards in an old house that pose a much greater risk than a hidden door. (knob and tube wiring, lead paint, asbestos...). I am assuming most houses with a crawl space are old. The added safety and security this door affords my family well out ways any perceived risks.

booga007 (author)2015-02-01

This doesn't look like a 'gripe' to me, it's constructive criticism. Something for the author to think about.

No-one ever knows everything, we're hear as a community to contribute. I've seen some angrier, 'know it all', posts that weren't helpful, but this is ok.

fjaswift (author)2015-02-01

I've been wanting to do this for a while. Thanks for the tutor

falcondob (author)2015-02-01

Oh for the want of a crawl space. The distance from plywood upstairs to plywood downstairs is only 20" and the width is about the same. Nonetheless, I can certainly make a place to hide valuables. Thanks and kudos. Great Instructable!

nathan.stoddard.18 (author)2015-02-01

This is just great for that home dungeon everyone needs! ;p

bmaverick (author)2015-02-01

If the crawl is exposed to a damp ground, I would suggest making a box enclosure that hangs from the floor underneath or depending on how the floor joist boards run, enclose that. To be even stealthier, some homes have cold air floor returns that use galvanized metal. One could make a fake return path that isn't connected to keep invasion to a minimum.

grimdaddy (author)2015-02-01

Neat idea! That is one huge crawl space. I usually only see belly in the mud crawl spaces. It looks like you have almost 4ft of crawl around room. I am glad I have a basement.

outlawamps (author)2015-02-01

Awesome... I have actually had this idea in mind myself for a number of years, just can't decide on a door location. Maybe this will inspire me to get back to planning.

You should look into sealing off your CS, if you haven't already done so. Do a search for 'all dry', or 'dry space' or similar. This was one of the best things I ever did to my house... Keeps things nice and dry, plus totally eliminated insects/spiders in the house.

dlewisa (author)outlawamps2015-02-01

One of my early instructables was on crawlspace encapsulation.

Nikiniku (author)2015-02-01


I knew that it could be done, and I've wanted to do it for several years, but your presentation has given me the extra push I needed to actually do the job. Thanks again.

stannickel (author)2015-02-01

I like this idea! Great instructions! I don't know for sure, but sometimes a box cutter isn't really up to the job of cutting precise edges. You may want to try a ceramic knife for cutting the carpet. I recently tried to cut a foam insulation board with a box cutter, and it made a mess of the edges. The ceramic knife made very nice and clean edges.

rwood10 (author)2015-02-01

I have been wanting one of these to be able to reach my water main supply but it is under the sink... With this video I think I can fond a way.. Excellent video an you did a great job..

kal5 (author)2015-01-31

Kudos! What a great idea.

M3G (author)2015-01-30

This makes me wish I had a crawl space. Nice work!

About This Instructable




Bio: I am married and have two daughters. I have owned a house painting company for the last 15 years. My goal is to retire early ... More »
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