Plywood and Door

FinnForm Data Sheet

The superior hardwood strength properties of Finnish White Birch combined with thin multiple veneer panel construction makes FinnForm the benchmark for quality in the plywood forming industry. The 200g/m² phenolic surface film on both faces provides very high reusability while producing smooth, well-compacted concrete. That's why architects and specifiers select FinnForm for high profile concrete projects throughout the country. There's only one FinnForm—easily identified by its red colored film faces.

Characteristics of Concrete Form Plywood

Strength and Elasticity

The following data for FinnForm^® was derived from thousands of in-use tests. The values are certified by the State Institute for Technical Research, Helsinki, Finland. A safety factor of 2.33 has been used in determining the allowable stresses. Deflection data were computed based on the formula:

Tabled data is for FinnForm^® only.

The structural data allows the form designer to predict with reasonable certainty, the maximum deflection that will occur under given loads. Consistent end-use results are dependent solely on proper form design and concrete placement practices.

Allowable Stresses For FinnForm^®

A = Moisture Content less than 19%.
B = Moisture Content 19% to 28%

Type of Stress

A—Effective
Cross-section
lbs./sq. in.

B—Effective
Cross-section
lbs./sq. in.

Extreme fibre in bending
Face grain II to span, 5 plies
Face grain II to span, 7 plies or more
Face grain—to span, 5 or 7 plies
Face grain—to span, 9 plies or more

3600
3600
3200
3600

2500
2500
2180
2680

Tension
II to face grain, 5 or 7 plies
II to face grain, 9 plies or more
—to face grain

3800
3600
3200

3380
3160
2650

Compression
II to face grain, 5 or 7 plies
II to face grain, 9 plies or more
—to face grain

2250
2100
1850

1450
1300
1200

Recommended Moduli of Elasticity for FinnForm^®

A = Moisture Content less than 19%.
B = Moisture Content 19% to 28%

Type of Stress

A—Effective
Cross-section
lbs./sq. in.

B—Effective
Cross-section
lbs./sq. in.

Bending (E)
Tension
Compression

2,030,000
2,400,000
2,320,000

1,830,000
2,140,000
1,960,000

Moments of Intertia, Section Moduli and Areas for FinnForm^®

All values are effective, i.e. only plies with grain direction parallel to the span are taken into account.

Sanded Plywood Thickness

No. of Plies

Face grain parallel to span- 12" widths

Face grain perpendicular to span- 12" widths

Nom.

Act.

Area Inches²

Section Modulus Inches³

Moments of Intertia Inches⁴

Area Inches²

Section Modulus Inches³

Moments of Intertia Inches⁴

Weight lbs./msf. (Approx)

1/4"
3/8"
1/2"
5/8"
3/4"

0.256"
0.366"
0.472"
0.638"
0.747"

5
7
9
12
14

1.75
2.41
3.17
4.34
4.98

0.0969
0.178
0.288
0.480
0.640

0.0124
0.0325
0.070
0.150
0.241

1.32
1.98
2.65
3.31
3.97

0.0527
0.120
0.225
0.395
0.555

0.00435
0.0166
0.045
0.112
0.183

930
1330
1765
2320
2715

Stock sizes: 8'x4', 10'x4', 12'x4', 8'x5', 10'x5', 12'x5'.

Please refer to FinnForm^® Technical Bulletin "Care & Storage" for additional handling and usage information.

Concrete Forms

All data is based on support spacings in inches. Deflection 1/270 or 1/16" (.0625) moisture content less than 19%. All load tables should be used as guides only. Data emplyed assumes plywood will be used the strong way (face grain parallel to span). Note: FinnForm^® is manufactured with the grain running in the narrow (4',5') direction unless otherwise noted. Plywood continuous over two (2) or more spans; support width minimum 1 1/2".

1/4"

Structural Data: M.O.E. 2,030,000

S .0969 | 0.0124 f (Bending) 3,600#

Max Loads at Indicated Spans: (PSF)

5.5"
1380

6"
1162

8"
654

10"
418

11"
346

12"
290

13"
248

14"
214

Max Loads at 1/270 Spans: (PSF)

5.5"
977

6"
752

8"
317

10"
163

11"
122

12"
94

13"
74

14"
53

3/8"

Structural Data: M.O.E. 2,030,000

S .178 | 0.0325 f (Bending) 3,600#

Max Loads at Indicated Spans: (PSF)

6"
2134

8"
1200

10"
768

11"
636

12"
534

13"
456

14"
392

16"
300

Max Loads at 1/270 Spans: (PSF)

6"
1972

8"
831

10"
426

11"
320

12"
246

13"
194

14"
155

16"
104

1/2"

Structural Data: M.O.E. 2,030,000

S .288 | 0.070 f (Bending) 3,600#

Max Loads at Indicated Spans: (PSF)

6"
3453

8"
1942

10"
1243

12"
863

14"
634

16"
486

18"
384

20"
311

Max Loads at 1/270 Spans: (PSF)

6"
3453

8"
1792

10"
917

12"
531

14"
343

16"
224

18"
157

20"
115

5/8"

Structural Data: M.O.E. 2,030,000

S .480 | 0.150 f (Bending) 3,600#

Max Loads at Indicated Spans: (PSF)

8"
3237

10"
2072

12"
1439

14"
1057

16"
809

18"
639

20"
518

22"
429

Max Loads at 1/270 Spans: (PSF)

8"
3237

10"
1966

12"
1137

14"
716

16"
480

18"
337

20"
245

22"
185

3/4"

Structural Data: M.O.E. 2,030,000

S .640 | 0.241 f (Bending) 3,600#

Max Loads at Indicated Spans: (PSF)

8"
4316

10"
2762

12"
1918

14"
1409

16"
1079

18"
853

20"
691

22"
572

Max Loads at 1/270 Spans: (PSF)

8"
4316

10"
2762

12"
1828

14"
1153

16"
772

18"
541

20"
395

22"
297

The data shown supercedes and replaces all previously published data for this product. January 1999