Sliding Garage Door Construction

[SeanG]

The door in my new garage will be sliding and will be made up of four leaves.

The leaves are hinged together and hang from the top onto a metal rail, apart from the fourth leaf which does not hang from the rail and is only supported by the hinge to the leaf beside it. (a diagram would help but I'm in work and can't upload pics at the mo).

So to open the door, leaf four would be unlocked, swung open and then the entire set of leaves will slide along the rail and round the corner of the garage.

I was planning on all the leaves being constructed as a Mortice & Tenon frame clad with tongue and groove.

Question 1) as the fourth leave is only hinged should I add a brace to the construction to combat sagging?

Question 2) if braced would it need to be skew notched into the bottom rail or could it be just sort of wedged into the corner?

Question 3) if the fourth leaf is braced (bottom of brace on hinge side) should the third leaf be braced as well and if so would the top of the brace go on the hinge side to stop the fourth leaf pulling it down.

Question 4) I want the finish to shown the grain, would stain or oil be better?

Question 5) what wood? – people have suggested Redwood on other posts for external gates/doors.

Question 6) Have I asked enough questions?

Sean

 

[inventor]

Question 1) as the fourth leave is only hinged should I add a brace to the construction to combat sagging?

Yes. It works just like an ordinary door.

Question 2) if braced would it need to be skew notched into the bottom rail or could it be just sort of wedged into the corner?

Ah, now there's a question. I looked into this in some detail for optimum gate design, maximum strength with minimum loading on the joints. I believe that the centreline of the brace should pass through the bottom hinge. That moves it over a fair way from where most people put it. So, I'd skew notch the brace into the hinged upright, near the bottom hinge, rather than putting it in the bottom corner or along the bottom rail.

Personally, I'd put the top end of the brace in the middle of the top rail of the door. That way, the top rail is balanced about the brace. It's unlikely people will swing on the outside edge of the door (unlike a farm gate) and the brace in the middle gives best stiffness for minimum load when the door is just sitting there. Again, this moves the brace over towards the hinge compared to most people's practice. Again, I'd skew notch the brace.

Question 3) if the fourth leaf is braced (bottom of brace on hinge side) should the third leaf be braced as well and if so would the top of the brace go on the hinge side to stop the fourth leaf pulling it down.

No, I wouldn't brace it, personally.

Imagining just the final two leaves hanging there on their own, they'll hang entirely happily with just one roller, that on the third leaf which is closest to the fourth leaf. If the third leaf distorts, it'll be pushing on the second leaf, etc. No, I don't think the third leaf will bend.

Question 4) I want the finish to shown the grain, would stain or oil be better?

No idea! Ask over on the finishing forum!

Question 5) what wood? – people have suggested Redwood on other posts for external gates/doors.

No idea again. Probably depends on the finish you 'll use. If it's redwood, that had better be real american redwood, and not british "redwood" which is usually scots pine.

Question 6) Have I asked enough questions?

Almost certainly not

 

[SeanG]

Thanks Inventor,

If I've understood your explanation, the brace on the fourth leaf will look like the right hand diagram below (the other two were other go's at getting the brace lined up to the hinge).


click on image for larger view


Time to move on to a more acurate sketchup plan, I can put the notches in then

thanks again.

Sean

 

[Benchwayze]

Hi Sean,

For my exterior, framed ledged and braced doors, I prefer:

Western Red Cedar for the frames. Nice and light, and weather resistant. If you can afford it, get some matchboard or shiplap made up from the same timber. Otherwise make do with matchboard of Scots Pine, and dose it well with a suitable shade of preservative, before you panel the door.

The next best is American, Southern Yellow Pine (Pitch Pine), if you can find that supplier up north who used to sell recalimed wharehouse chamber joists. New stuff is available at George Sykes in Atherstone, Warks.

Douglas Fir is good, clean and nice to work but needs preservative for use outside.

Oak is the best. Minimal maintenance and lasts for aeons, but don't use steel screws/nails because of staining from reaction of steel with tannins in the timber.

Finally, if you have to use redwood, try to get American variiety.
UK redwood is generally passable at best.
Okay you could use iroko or some of the mahoganies, but let's not get ridiculous eh?

Other forumites will have their favourites, but there you have mine.

I wish you luck.

John

 

[inventor]

Thanks Inventor, If I've understood your explanation, the brace on the fourth leaf will look like the right hand diagram below (the other two were other go's at getting the brace lined up to the hinge).


click on image for larger view

Yes.

However, you do add an interesting detail - A middle rail across the door to which the top of the brace connects. I'm not sure where the best place to put that is. I'll think about it!

Meanwhile, I suggest you go ahead and make your doors. Waiting for me to think about things has been known to take decades.