Trapdoor hinges

[Mickwhitt 4,621]

OK guys, the wonderful wife requires a trapdoor making to fit over a staircase that goes down into our garage. 

If we cover the stairs we can use the room as a separarate bedroom, but open it up if we need to use the stairs. 

There are companies that make such things and we had a quite today of £5,000 for a floor door 1.7m x 0.8m

 

That's a lot of the folding stuff....

 

So I can make my own hatch no problemo,  but what about the hinges?

 

I've seen complex multi piece hinges that look quite fiddly to set up.

 

And I've seen what look like simple bar and pin hinges which I'm pretty sure I can fabricate.

 

Does anyone have any experience of making such a door in the floor. Especially the hinges, I need a clue to designing a suitable simple but strong hinge.

 

Thanks guys.  Mick 

 

[SylvanLakeWH 25,545]

I'd run a 2x4 along wall at same grade as floor minus door thickness. Large door hinges off the 2x4 with door going flat against wall where tv is when up and laying flat at floor grade when down. Gap in head wall i would put a simple plywood board that hinges down or latches up when stairs in use.

[formariz 11,987]

Do you want this door to fit flush with floor to match it in appearance and if so is it going to be stepped on frequently therefore needing to carry substantial weight and vibration? 

Edited October 12, 2023 by formariz

[formariz 11,987]

As a beginning suggestion I would make it to look like part of floor when closed. Part to cover head space would hinge onto floor door so one would fold that down first and then flip up the two doors together against wall. A bit of planning is needed such as location of pivoting points to accommodate thickness of both doors when open against wall.  I am not sure what complex multi piece hinges you are referring to but it may be what we here refer to European hinges which are concealed . There are literally dozens of variations to accommodate any situation and thickness of material. The benefit they have is basically the opposite of what you are thinking. They will allow a unlimited number of adjustments to compensate for irregularities in field conditions or installation faults. They are however hard and intimidating to use and understand to the untrained individual. As you say “fiddly to set up”.The correct type also has to be chosen in order to fulfill the correct functions of a particular job.

Again it all depends on how you want the job to look . A clean seamless look when everything is closed or just a functional utilitarian look without too much regard for aesthetics . Those choices will determine what type of hinge you will use. In either case there are available hinges that will work on any possible circumstances without having to build them. 

[Handy Don 12,215]

The array of possible hinges can bewilder even a craft-competent person. @formariz is right on the money -- primary decisions are will it need to hold weight and must it be flush with the floor when closed.

I’d also note, that I wouldn’t permit an open stair with no railing in my home since I host children often. It’s possible that the door, when open, could form a wall blocking the stairway from “side entry”.

[Mickwhitt 4,621]

Gentlemen,  again Red Square hits paydirt. 

 

I've had a look round the Web and found what I think are just the hinges for the job. 

 

90 degree opening so they will hold the trap door up as a side wall when open to prevent falling in. 

 

perfect for the style of door i am thinking aboit.

Plenty of literature with them so I'm going to buy a set to play with and develop the idea.

 

To answer questions asked in your responses, yes its going to be weight bearing but it's along a wall so won't be stepped on all the time. Yes it's going to be flush fitting and as near invisible as I can achieve. I may look at some kind of actuator to lift it, probably electric, but air would be fun as I have a huge compressor feed.

 

 

[CCW 1,295]

I am also looking at the right end of the stairs where there is head clearance as you descend.  Are you going to cover that?  Perhaps a door that can be slid up the was when access is needed and down to prevent people from wandering over the edge of you door floor.

 

[Mickwhitt 4,621]

CCW yes the head clearance end will have a hinge up flap to allow me to walk down without banging my crust. 

Doing the work myself will allow me to design around the issues I find as I go along. Having a door made would be more expensive and not exactly as needed fir the conditions I have. 

I'm also going to hinge the floor trapdoor to the right hand side looking down the stairs to provide a barrier when it's open. 

[953 nut 55,197]

Have you considered using a set of "Swing Clear" hinges? Also, a solid door would be a very good option for the floor section.

 

[Handy Don 12,215]

I dont

9 minutes ago, 953 nut said:

a solid door would be a very good option for the floor section.

I’d be very careful of using a door in a load-bearing situation, unless it was solid and one-piece.

We built a similar stair-covering “door in the floor” at my Dad’s camp to close off the loft at night for the safety of small children. We used two layers of ½” plywood with stringers sandwiched between on the edges and 3 or 4 spaced across the short span. Glued and screwed. Door rested on ledges in the “jamb” when closed, similar to standard stops but using strips of ¾” plywood. We didn’t bother with concealed hinges (it’s a CAMP, right?). It supported adult weight with no issues and wasn’t too heavy to lift for a 7- or 8-year old. Held open with a simple hook and eye to a roof support beam.

[Mickwhitt 4,621]

The idea is to create an extension of the floor area when we don't need stair access, so the door, flap, trap needs to be strong enough. 

Most of the ones I've seen online have a steel subframe with a thick ply deck, which is the way I am going to go.

I'm using these special hinges as they are completely enclosed and invisible when the trap is shut, ideal for our purpose. 

Weight of the finished door is obviously a consideration as I have to be able to open it. But I'm looking into various options from gas struts to pneumatic lift cylinders, electric actuators look too slow. 

When the hinges arrive I will make a model of the trap to see how things fit before I get welding. 

[CCW 1,295]

Could you use a simple counterweight system?  Would work unless you do not want anything to be visible.

[Mickwhitt 4,621]

I'd looked at a counter weight but there isn't room to include it.

The trap should be easy enough to lift manually but with the march of time I think I'd be thankful for having fitted power opening.

 

[Handy Don 12,215]

13 minutes ago, Mickwhitt said:

thankful for having fitted power opening.

Electric linear actuators are slow but can be quite powerful. You might be able to take advantage of leverage.

Gas struts both for opening assistance and for holding it open are a great idea.

[953 nut 55,197]

15 hours ago, Handy Don said:

15 hours ago, 953 nut said:

a solid door would be a very good option for the floor section.

I’d be very careful of using a door in a load-bearing situation, unless it was solid and one-piece.

          I should have said "LUMBER CORER".  Many solid core doors these days are particle board core.

[wallfish 16,994]

Just throwing this out there as a possibility

Does the bed fit in that space? Wheels on the bed and then there's no need to get to fancy with the door(s) as it will be covered by the bed anyway. Plus avoids walking on it. Would it even require a door if the bed covers it well. Then just a removable track or something to support that rear right corner of the bed.

Roll the bed away (Or other piece of furniture to gain access to the stairs.

 

[SylvanLakeWH 25,545]

 

The trundle bed approach... 

[formariz 11,987]

Just keep in mind that whatever you design and build should have a safeguard system to support it from collapsing into stairs should hinges fails. That can simply be a stop or rest onto which door will rest anyway but important at hinge side. 

[Mickwhitt 4,621]

Well, it's funny the mobile bed should come up...

When we were just going to convert the room back to a bedroom I had that very idea. Track system to run the bed on and a pair of steel pin and socket supports on the wall to support that back corner.

But she who must be obeyed would not sign off on the deal so it was shelved.

 

As regards support for the door when closed I'm making a frame for it to sit in which is fully supported. Kind of stealing the best ideas from designs I've seen on Pinterest. 

 

I will run anything past you guys before I commit to it. Especially the control system. I would love air power as it is so quick and powerful, but I'm still thinking about it.

 

 

[Mickwhitt 4,621]

Bit of progress today, I fitted a wall plate to the hinge side and cut a piece of 19mm flooring ply for the trap door. 

Fitted a wall plate on the closure side and checked that all seems to fit OK.

Next it will be making the frame and hatch for the head room access.

Then hopefully the hinges will have arrived and I can start planning the support frame for the door. 

 

[wallfish 16,994]

 

Just in case you're not getting enough motivation from the other half I'll help you out

My wife--

" What kind of wood is that" 

"The color on the left is different from the other end"

"Did you put enough screws to hold it?"

"Is it going to hold me?"

"You test it first"

"I see a little space on the corner!"

"Are you going to be working on that all day? I need ___________ fixed too!"

[formariz 11,987]

4 hours ago, wallfish said:

 

 

Just in case you're not getting enough motivation from the other half I'll help you out

 

My wife is very good with those things. Only the same two questions always; “is it going to make dust?” And “How long is it going to take?”. 

[953 nut 55,197]

19 hours ago, wallfish said:

"Is it going to hold me?"

"You test it first"

Didn't you know that husbands are expendable and can serve a crash test dummies.    

15 hours ago, formariz said:

My wife is very good with those things. Only the same two questions always; “is it going to make dust?” And “How long is it going to take?”. 

Before we built our new house my wife thought it would be better to add on to the old house and remodel everything. She became a believer when we remodeled the utility room to make it more functional.Everything had to come out and was stored in the living room while I was redoing the plumbing and electrical to accommodate the new washer, dryer and water heater placement. Then the new drywall and associated dust followed by the smell of the flooring adhesive followed by the contact cement for the formica. At that point she was in total agreement that building a new house and renting out the old one was a much better idea.

[Mickwhitt 4,621]

The new hinges have arrived and they are very solid.

I've made a small version of the flap to see how the hinges fit and work.

 

[Handy Don 12,215]

6 hours ago, Mickwhitt said:

The new hinges have arrived and they are very solid.

I've made a small version of the flap to see how the hinges fit and work.

 

Nicely done, sir. Great that the hinges are only supporting the door weight and only whilst the door is open. Carry on!

Edited October 21, 2023 by Handy Don