RIGID FRAME MULTI-SPAN (RF_*)
Available with either solid web or open web rafters.

Used where interior columns do not impair function of building.  Provides maximum width at lower cost than Rigid Frame Clear Span frames.  Ideal for manufacturing plants and warehouses.

RIGID FRAME MULTI-SPAN (RF_*)
A Rigid Frame Multi-Span frame has a single ridge and consists of welded-up rafter and sidewall column sections.  Sidewall columns are pinned at base and continuous at haunch.  Rafter is continuous throughout.  All interior columns are pipe sections and are pinned at both ends.  Frames are designed by computer analysis in accordance with accepted engineering practices.

Open Web Frames
Rigid Frame Multi-Span Frames with open web rafters are also available.  These rafters have parallel chords; sidewall columns are welded-up (solid web) sections; interior columns are pipe sections.

*Numerical digit denotes number of spans (RF4 illustrated).

Clearances and Reactions
Due to the broad parameters available, it is impractical to give minimum clearances and column reactions for the multiple combinations of width, spans, eave height, roof slope, bay spacing, load and codes that are available.  However, for representative samples of the information that Ceco can furnish, refer to the tables.

Clearances and reactions in the tables are given for frames with welded-up (solid web) rafter sections.  They are not applicable to open web frames.

For actual frame clearances and reactions for any specific building, and/or for open web frames, contact the nearest Ceco manufacturing facility.
 

REPRESENTATIVE
CLEARANCE DIMENSIONS
1:12 ROOF SLOPE
 

BAY SPACING  --  25ft.
ROOF SLOPE  --  1:12
LIVE LOAD  --  LL (psf)
WIND LOAD  --  WL (mph)
WIND LOAD APPLIED IN ACCORDANCE WITH MBMA (1996)

*C =  Minimum clearance other than at knee (dimension B).  All points where rafter changes shape are checked and vertical dimension to lowest of these points is given.

 **Clearances shown are approximate.  Actual clearances may be somewhat different.
Note:  1.  Clearances shown are approximate.  Actual clearances may be somewhat different.
           2.  Live loads greater than 30 pounds must be quoted.  Please contact the estimating department at your regional office.
 

REPRESENTATIVE
FRAME REACTIONS
1:12 ROOF SLOPE

NOTES:
1. Dead load equals self weight of members.
2. Wind load is applied in accordance with MBMA (1996).
3. Negative value of reaction indicates direction opposite to that shown on sketch.
4. Reactions shown are approximate only and are not exact submittal values.
5. Reactions for various load combinations may be obtained by adding or subtracting the appropriate values.
6. Forces on the foundation will act in the opposite direction to the direction of the frame reactions.

Bay Spacing -- 25 ft.
Roof Slope -- 1:12
Live Load -- 20 psf
Wind Load -- 80mph

MODIFYING FACTORS:
To obtain approx. reactions for other bay sizes, live loads, and/or wind loads use the following rules:
 

BAY SIZE: (up to 30’)	Divide all reactions shown by 25 then multiply by the bay length required.		LIVE LOAD:	Divide live load reactions shown by 20 than multiply by the live load required.
			WIND LOAD:	Multiply the wind load reactions shown by the applicable factor: 70 mph use 0.8 90 mph use 1.3 100-mph use 1.6 110-mph use 1.9 120 mph use 2.3