\ Bifold Doors: Wood Buildings - Wall, Bracing, Placement Options
Schweiss Bifold Doors
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Wood Building Details

UNDERSTANDING LARGE MOVING DOORS . . . HYDRAULIC OR BIFOLD DOORS

Quote... A farmer asked...
When the door is hanging straight out there, you better have something strong holding those cylinders. Doesn't the door put a lot of stress on the building?
That goes for both style of doors

Quote... A engineer once said...
The doors WILL find the weak points in our building design. Many wood building engineers have a tendency to get lax with the design of the door supports and framing surrounding your doors and forget that we not only have to support the weight and wind on the door, we also have to support its operation.

*NOTE: "It's better to overbuild your building than to make costly repairs later"

Myths That Can't Be Ignored

Myth:

  1. Building does not have to be made stronger.
  2. Building does not have to be modified to hold a hydraulic / bifold door.
  3. Building does not have to be engineered with extra reinforcing to accept a Hydraulic/Bifold Door.
  4. Door does not hang on your building . . . What does the door & frame attach to?

COMMON Myth:

  1. The door is self-supporting and does not add any load to your building.

ASK YOURSELF:

Is the door like a billboard? Could the door be erected in your parking lot ? The door could not possibly be erected independent of your building. The only way that the door would not add load to your building is if they were selling you a billboard that would lift itself without falling over. Otherwise, all of the forces and loads from the door opening and from windloads gets transferred through the door sub-framing to your building.

Red Flag:

  1. When anyone tells you that the door does not put load your building, that should be a red flag to tell you that they don't understand large moving doors.
  2. Door can be left open in windy conditions " BUT " can the buildings withstand the forces...

USE COMMON SENSE When Designing your building to accept a Hydraulic / Bifold Door
And refer to the
SCHWEISS DOOR SPECIFICATION SHEETS and Reactions sheet to help understand the forces.
Schweiss Specs are supplied with each door.



HYDRAULIC DOOR FORCES

Horizontal Door Column Bracing.... increase the torsional stiffness of the door column.

  1. Hydraulic doors come with two powerful cylinders that are pre-mounted to a vertical sub-frame, one cylinder on each side of the door opening.
  2. The sub-frame that the hydraulic cylinders attach to must be fastened to the buildings door side columns.
  3. The hydraulic cylinders exert strong rotating forces to the buildings door side columns as the door is being operated.
  4. It is important to limit the rotation of the door side columns as the door is opening and closing, also when in the open position.

Helpful

  1. To aid in limiting this rotation, horizontal braces are strongly recommended at the point on the door column where the cylinder attaches.
  2. Horizontal bracing is used to stop the doors vertical sub-frame, cylinder bracket and buildings door side column from twisting.
  3. The door cylinders and cylinder plate attach to vertical sub-frame members which are all connected to the buildings door side column on each side of the door opening.
  4. To help resist the torsional forces in the door side column, use horizontal bracing to the next adjacent building column in the plane of the door.
  5. These horizontal braces help resist the torsional load in the door side column.


THINGS TO CONSIDER WHEN PREPARING YOUR BUILDING FOR A HYDRAULIC/BIFOLD DOOR

#1. . . . . Is bracing necessary and what should the bracing look like.
#2. . . . . Poorly designed buildings and buildings that are designed properly.
#3. . . . . Old and new buildings.

First:

The strength of columns and beams is a function of the material (steel or wood) and its size (2x6 is stronger than 2x4 because it has more material) and how it is braced (stability). Even very large (seemingly strong) columns do not have much capacity if they are not braced.

The larger the column size, the less bracing it usually needs. It is possible to design columns as (unbraced) but the size of the column tends to become very large and would likely be aesthetically unacceptable.

If we are going to brace columns, what does the brace need to look like? Braces on columns need to brace each axis of the column. You typically need less bracing on one axis of the column than the other. You also need to make sure that the bracing is effective. Effective bracing keeps the column from buckling (like when you put a straw between your fingers to see it bend), it also has to keep it from rotating. Rotation can be caused by axial load, when the entire column is loaded, if the outside face of the column is braced, but the inside face or flange is not. For columns that have an unbraced inside face or flange, additional bracing is usually required. Metal building people typically use flange braces, but the bracing may be horizontal to a second column that is near the column you want to brace (lean-on bracing).

Second

This leads to the second topic of building design.
The building could be considered to be "acceptably designed" if the designer is told the correct loads that are going to be put on the building (dead load, torsion, eccentric loading, etc.) and they have designed the building to resist all of those loads. A "better design" would consider the desires of the customer. For example, if the customer were going to have an interior finish, you want the braces designed so that they did not extend beyond the inside face of the column.

Third

The question of existing buildings:
Existing buildings can be a bigger problem. They were probably not designed for whatever you want to do or add to your building. The original designer or building company may not be willing to help. It is important to either have a qualified engineer or the original designer or building company design the modification using the correct loads and eccentricity information. All of the "recommendations" that Schweiss has on their spec sheets are good basic common sense recommendations that go a long way toward making the building right. The final responsibility lies with the building owner of an existing building. If they get a qualified engineer or the original engineer or building company to help them, then they can take that responsibility. The qualified engineer or original engineer or building company can look at Schweiss' recommendations and decide what is really required.

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Wood Building Details (A)

Bi-fold Hanger door mounted to wood building endwall

Wood Building Details (B)

Wood building with bifold door mounted to both endwall and sidewall

End Wall

Side Wall

Wood Building Details (C)

Wood building with free standing header mounted to both endwall and sidewall

End Wall

Side Wall

Wood Building - Header Built into Endwall (Style 1)

Wood building with free standing header built into endwall

Shows where a header is installed in an endwall of a building. The header is positioned up above the bottom of the rafter so you won't lose any headroom!

Wood Building Details
Details of wood building with free standing header built into endwall

Open End Wall Rafters - Header Placements
We work with old or new buildings to make your Bi-Fold Door work.

Three 2x6's - Vertical Stiffener

Endwall Sheeting Above the
Bi-fold Door Frame & hinges

Bolts

Built-in
Header Plate

Attach
Door Here

Bolts

Clear Opening - Between Columns

Distance To Keep The Building Sheeting Back

Wood Building - Bottom Cord as Header (Style 2)

Wood building with bottom cord as header for bifold door

Shows where a header is, using the bottom chord in an endwall of a building. The engineered rafters can be doubled up for sufficient support.

Details of wood building with bottom cord as header for bifold door

Three 2x6's - Vertical Stiffener

Endwall Sheeting Above the
Bi-fold Door Frame & hinges

Bolts

Built-in Header Plate

Attach
Door Here

Bolts

Side Column

Side
Column

Clear Opening - Between Columns

Distance To Keep The Building Sheeting Back

Wood Building - All About Additional Bracing

Detail of additional bracing used to support bifold doors attached to your building

The Customer is Responsible for the Building Structure & Bi-Fold Door Header.

Header Built Into The Endwall

Columns Must
Be Full Length

Push Door Header Bolts Through The Vertical Stiffeners

2x6's To The Back To Next Rafter

Triple- Vertical Stiffeners - 3 - 2x6's By Each
Hinge Location

Double The Side
Columns On
Larger Doors

This Bottom Chord
Must Not Bow
Outward

Additional Header PLate Or Blocking

Side Columns Must Be
Full Length

Two Rafters
Back To Back

Bolt Rafter
To Each
Side Column

Go Beyond Frost Level

Bi-Fold Door Header Endwall - Side View

Detail drawing of bifold door mounted to building endwall

The Customer is Responsible for the Building Structure & Bi-Fold Door Header.

Need A Backer Plate To
Apply The Bldg. Sheeting
To This Area

2nd Building Rafter in
From The Endwall

Double End
Wall Rafter

Built In
Header Plate

Wedge = D

3rd

Ceiling

Added Bracing

Detail drawing of added bracing used to support a bifold door attached to your building

2 X 6 Vertical

Triple Vertical Stiffeners- 3- 2x6's By Each Hinge Location

Tie Back Brace

2 X 6 Vertical

Need A Backer Plate
To Apply The Bldg.
Sheeting To

Header Bolt

Ceiling

The Customer is Responsible for the Building Structure & Bi-Fold Door Header.

Bolting Rafters to the Side Columns

Bi-fold door side columns bolted to building trusses

Bolt Truss To The Side Columns

Bolt

Truss

Side Columns-door Rolls Up On - Must Be Full Length

The Customer is Responsible for the Building Structure & Bi-Fold Door Header.

Vertical Braces

Vertical braces for bi-fold doors

Double Ply Truss

Triple 2x6 Vertical Stiffener
TOP VIEW

Bottom Chord Brace At Each Stiffener (2x6)
TOP VIEW

2x6 Web
Blocking

Note:
On double endwall trusses where the outside ply is a "Gable Type" truss and the inside
is an "Intermediate Truss", there will be locations where there is a 1.50" space between
the vertical stiffener and the horizontal members of the gable truss.

The Customer is Responsible for the Building Structure & Bi-Fold Door Header.

Door Placement

Face Mount for bifold door to wood building

(A) Face Mount

Sheeting Is Offset

Building Side Column

Door shall be mounted on the exterior walls of building

Outside of Building

Bi-Fold Doors Overlay the Side Columns on the Face of the Building

Flush Mount for bifold door to wood building

(B) Flush Mount

Sheeting Is On the Same Plain

Building Side Column

Door shall be mounted flush with the exterior walls of building

Outside of Building

Placement of Bi-Fold Door onto the Building

Detail drawing of double endwall rafter

Note: Use The Same "Additional Support Bracing" As Style 1 On This Style Of Endwall Rafter

Triple Vertical Stiffeners
(3) 2x6's By Each Hinge
Location

Bolt Rafter To
Each Side Column

Additional Header Plate (filler Block)

How To Strengthen
Your Endwall Rafter

Detail:
Bolt Through Door
Header

The Customer is Responsible for the Building Structure & Bi-Fold Door Header.

Side Columns Must Be Full Length
(on Larger Doors Double The Side
Columns)

Wood Building with Free Standing Header

Measurement guide for bi-fold Hanger door mounted to endwall with free standing header

Free Standing Header

Wood Building Sidewall with Free Standing Header

Wood building endwall using a free standing header

Substitute Hangar Bracket
3" x 4" x 1/4" Angle Extension Bracket

Sized per door / place by each hinge)

SIDE WALL

Lateral Bracing

Wood Building Side Column

Free Standing Header

Wood Building Sidewall with Free Standing Header

Side view of free standing header mounted to sidewall of wood building

Building Sheeting

Extension Header
Bracket

Single Hinge

Free Standing Header

Lateral Bracing

Double 2x12

Door Frame

Wood Building side column