Truss Design - Revision history

Marcin: /* 20' Trusses for SH6 */

2025-11-09T01:48:34Z

20' Trusses for SH6

← Older revision		Revision as of 01:48, 9 November 2025
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	=20' Trusses for SH6=		=20' Trusses for SH6=
	*See calculations at SH6 - [https://docs.google.com/presentation/d/1ze61chProYdNDnC5Q7xCx283QmyARcUHXUF9RRuQWb0/edit?slide=id.g379d85e8dec_4_0#slide=id.g379d85e8dec_4_0]		*See calculations at SH6 - [https://docs.google.com/presentation/d/1ze61chProYdNDnC5Q7xCx283QmyARcUHXUF9RRuQWb0/edit?slide=id.g379d85e8dec_4_0#slide=id.g379d85e8dec_4_0]
	<html> <iframe src="https://docs.google.com/presentation/d/e/2PACX-1vTDqci3-QK1Q8RBVYW4V4963XyD0T5GxYI9rGrsPj9gJcdp2Os0cd2pSW2dA_85VnaJkBLHuUYvWT4u/pubembed?start=false&loop=false&delayms=3000" frameborder="0" width="480" height="389" allowfullscreen="true" mozallowfullscreen="true" webkitallowfullscreen="true"></iframe> </html>		<html> <iframe src="https://docs.google.com/presentation/d/e/2PACX-1vTDqci3-QK1Q8RBVYW4V4963XyD0T5GxYI9rGrsPj9gJcdp2Os0cd2pSW2dA_85VnaJkBLHuUYvWT4u/pubembed?start=false&loop=false&delayms=3000#slide=id.g379d85e8dec_4_0" frameborder="0" width="480" height="389" allowfullscreen="true" mozallowfullscreen="true" webkitallowfullscreen="true"></iframe> </html>

	[https://docs.google.com/presentation/d/1ze61chProYdNDnC5Q7xCx283QmyARcUHXUF9RRuQWb0/edit?slide=id.g379d85e8dec_4_0#slide=id.g379d85e8dec_4_0 edit]		[https://docs.google.com/presentation/d/1ze61chProYdNDnC5Q7xCx283QmyARcUHXUF9RRuQWb0/edit?slide=id.g379d85e8dec_4_0#slide=id.g379d85e8dec_4_0 edit]

Marcin: /* 20' Trusses for SH6 */

2025-11-09T01:48:15Z

20' Trusses for SH6

← Older revision		Revision as of 01:48, 9 November 2025
Line 10:		Line 10:
	=20' Trusses for SH6=		=20' Trusses for SH6=
	*See calculations at SH6 - [https://docs.google.com/presentation/d/1ze61chProYdNDnC5Q7xCx283QmyARcUHXUF9RRuQWb0/edit?slide=id.g379d85e8dec_4_0#slide=id.g379d85e8dec_4_0]		*See calculations at SH6 - [https://docs.google.com/presentation/d/1ze61chProYdNDnC5Q7xCx283QmyARcUHXUF9RRuQWb0/edit?slide=id.g379d85e8dec_4_0#slide=id.g379d85e8dec_4_0]
	*<html> ~~________________________________~~ </html>		<html> <iframe src="https://docs.google.com/presentation/d/e/2PACX-1vTDqci3-QK1Q8RBVYW4V4963XyD0T5GxYI9rGrsPj9gJcdp2Os0cd2pSW2dA_85VnaJkBLHuUYvWT4u/pubembed?start=false&loop=false&delayms=3000" frameborder="0" width="480" height="389" allowfullscreen="true" mozallowfullscreen="true" webkitallowfullscreen="true"></iframe> </html>

	[~~_______________________________________~~ edit]		[https://docs.google.com/presentation/d/1ze61chProYdNDnC5Q7xCx283QmyARcUHXUF9RRuQWb0/edit?slide=id.g379d85e8dec_4_0#slide=id.g379d85e8dec_4_0 edit]

	=Day 5 - OSB Scabs=		=Day 5 - OSB Scabs=

Marcin: /* 20' Trusses for SH6 */

2025-11-09T01:47:42Z

20' Trusses for SH6

← Older revision		Revision as of 01:47, 9 November 2025
Line 10:		Line 10:
	=20' Trusses for SH6=		=20' Trusses for SH6=
	*See calculations at SH6 - [https://docs.google.com/presentation/d/1ze61chProYdNDnC5Q7xCx283QmyARcUHXUF9RRuQWb0/edit?slide=id.g379d85e8dec_4_0#slide=id.g379d85e8dec_4_0]		*See calculations at SH6 - [https://docs.google.com/presentation/d/1ze61chProYdNDnC5Q7xCx283QmyARcUHXUF9RRuQWb0/edit?slide=id.g379d85e8dec_4_0#slide=id.g379d85e8dec_4_0]
			*<html> ________________________________ </html>

			[_______________________________________ edit]

	=Day 5 - OSB Scabs=		=Day 5 - OSB Scabs=

Marcin: /* Notes */

2025-11-09T01:40:25Z

Notes

← Older revision		Revision as of 01:40, 9 November 2025
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	*'''Point - keep full OSB sheet at ends. Keep full chord in middle.'''		*'''Point - keep full OSB sheet at ends. Keep full chord in middle.'''
	*Truss weight - ~100 lb [https://chatgpt.com/share/68773df8-8118-8010-adbe-53862c099261]		*Truss weight - ~100 lb [https://chatgpt.com/share/68773df8-8118-8010-adbe-53862c099261]

			=20' Trusses for SH6=
			*See calculations at SH6 - [https://docs.google.com/presentation/d/1ze61chProYdNDnC5Q7xCx283QmyARcUHXUF9RRuQWb0/edit?slide=id.g379d85e8dec_4_0#slide=id.g379d85e8dec_4_0]

	=Day 5 - OSB Scabs=		=Day 5 - OSB Scabs=

Marcin: /* Redo Original for 50 PSF */

2025-11-09T01:36:15Z

Redo Original for 50 PSF

← Older revision		Revision as of 01:36, 9 November 2025
Line 21:		Line 21:
	*Single truss no longer works with 20' span - but works with an 8' reinforcement. [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]		*Single truss no longer works with 20' span - but works with an 8' reinforcement. [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]
	==Redo Original for 50 PSF==		==Redo Original for 50 PSF==
	*32' truss - 16' reinforcement on mid of '''6' supported 32' truss''' still works for 50 psf! [https://chatgpt.com/share/6875ac72-d4a4-8010-9b88-122dc2123679]. '''6' supported''' means that an auxiliary side truss sticks out from the side walls, overlapping the main truss 2' for a good connection. The 'effective span' of main truss is measured from the end of the supporting truss.		*{{check}}. This is what we are doing for the [[Hangar]]: 32' truss - 16' reinforcement on mid of '''6' supported 32' truss''' still works for 50 psf! [https://chatgpt.com/share/6875ac72-d4a4-8010-9b88-122dc2123679]. '''6' supported''' means that an auxiliary side truss sticks out from the side walls, overlapping the main truss 2' for a good connection. The 'effective span' of main truss is measured from the end of the supporting truss.
	*24' truss - with 16' span, works at 50 psf [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]. Note for 16' walls - we have 15' span actually when using 2x6 lumber - and SPF #2 orks, while 16' fails by 8%.		*24' truss - with 16' span, works at 50 psf [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]. Note for 16' walls - we have 15' span actually when using 2x6 lumber - and SPF #2 orks, while 16' fails by 8%.
	*{{Check}}24' truss - with 20' span - needs 16' reinforcement - [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]. '''This is the design we are using for the [[Hangar]] to achieve a 32' clear section in the middle: 20' effective span + 6' support on each side. The supporting trusses are 16' long - 2' overhang of roof - 8' over side rooms - and 6' supporting section in the middle. With a telehandler - 5 of the 52' long trusses can be bound together with roof OSB, rim boards, and soffit - and lifted in 52'x8' modules.		*{{Check}}24' truss - with 20' span - needs 16' reinforcement - [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]. '''This is the design we are using for the [[Hangar]] to achieve a 32' clear section in the middle: 20' effective span + 6' support on each side. The supporting trusses are 16' long - 2' overhang of roof - 8' over side rooms - and 6' supporting section in the middle. With a telehandler - 5 of the 52' long trusses can be bound together with roof OSB, rim boards, and soffit - and lifted in 52'x8' modules.

Marcin: /* Redo Original for 50 PSF */

2025-11-09T01:35:35Z

Redo Original for 50 PSF

← Older revision		Revision as of 01:35, 9 November 2025
Line 21:		Line 21:
	*Single truss no longer works with 20' span - but works with an 8' reinforcement. [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]		*Single truss no longer works with 20' span - but works with an 8' reinforcement. [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]
	==Redo Original for 50 PSF==		==Redo Original for 50 PSF==
	*32' truss - 16' reinforcement on mid of '''6' supported 32' truss''' still works for 50 psf! [https://chatgpt.com/share/6875ac72-d4a4-8010-9b88-122dc2123679]. '''6' supported''' means that an auxiliary side truss		*32' truss - 16' reinforcement on mid of '''6' supported 32' truss''' still works for 50 psf! [https://chatgpt.com/share/6875ac72-d4a4-8010-9b88-122dc2123679]. '''6' supported''' means that an auxiliary side truss sticks out from the side walls, overlapping the main truss 2' for a good connection. The 'effective span' of main truss is measured from the end of the supporting truss.
	*24' truss - with 16' span, works at 50 psf [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]. Note for 16' walls - we have 15' span actually when using 2x6 lumber - and SPF #2 orks, while 16' fails by 8%.		*24' truss - with 16' span, works at 50 psf [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]. Note for 16' walls - we have 15' span actually when using 2x6 lumber - and SPF #2 orks, while 16' fails by 8%.
	*{{Check}}24' truss - with 20' span - needs 16' reinforcement - [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]. '''This is the design we are using for the [[Hangar]] to achieve a 32' clear section in the middle: 20' effective span + 6' support on each side. The supporting trusses are 16' long - 2' overhang of roof - 8' over side rooms - and 6' supporting section in the middle. With a telehandler - 5 of the 52' long trusses can be bound together with roof OSB, rim boards, and soffit - and lifted in 52'x8' modules.		*{{Check}}24' truss - with 20' span - needs 16' reinforcement - [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]. '''This is the design we are using for the [[Hangar]] to achieve a 32' clear section in the middle: 20' effective span + 6' support on each side. The supporting trusses are 16' long - 2' overhang of roof - 8' over side rooms - and 6' supporting section in the middle. With a telehandler - 5 of the 52' long trusses can be bound together with roof OSB, rim boards, and soffit - and lifted in 52'x8' modules.

Marcin: /* Redo Original for 50 PSF */

2025-11-09T01:34:13Z

Redo Original for 50 PSF

← Older revision		Revision as of 01:34, 9 November 2025
Line 21:		Line 21:
	*Single truss no longer works with 20' span - but works with an 8' reinforcement. [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]		*Single truss no longer works with 20' span - but works with an 8' reinforcement. [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]
	==Redo Original for 50 PSF==		==Redo Original for 50 PSF==
	*32' truss - 16' reinforcement on mid of 6' supported 32' truss still works for 50 psf! [https://chatgpt.com/share/6875ac72-d4a4-8010-9b88-122dc2123679]		*32' truss - 16' reinforcement on mid of '''6' supported 32' truss''' still works for 50 psf! [https://chatgpt.com/share/6875ac72-d4a4-8010-9b88-122dc2123679]. '''6' supported''' means that an auxiliary side truss
	*24' truss - with 16' span, works at 50 psf [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]. Note for 16' walls - we have 15' span actually when using 2x6 lumber - and SPF #2 orks, while 16' fails by 8%.		*24' truss - with 16' span, works at 50 psf [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]. Note for 16' walls - we have 15' span actually when using 2x6 lumber - and SPF #2 orks, while 16' fails by 8%.
	*{{Check}}24' truss - with 20' span - needs 16' reinforcement - [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]. '''This is the design we are using for the [[Hangar]] to achieve a 32' clear section in the middle: 20' effective span + 6' support on each side. The supporting trusses are 16' long - 2' overhang of roof - 8' over side rooms - and 6' supporting section in the middle. With a telehandler - 5 of the 52' long trusses can be bound together with roof OSB, rim boards, and soffit - and lifted in 52'x8' modules.		*{{Check}}24' truss - with 20' span - needs 16' reinforcement - [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]. '''This is the design we are using for the [[Hangar]] to achieve a 32' clear section in the middle: 20' effective span + 6' support on each side. The supporting trusses are 16' long - 2' overhang of roof - 8' over side rooms - and 6' supporting section in the middle. With a telehandler - 5 of the 52' long trusses can be bound together with roof OSB, rim boards, and soffit - and lifted in 52'x8' modules.

Marcin: /* Redo Original for 50 PSF */

2025-11-09T01:31:34Z

Redo Original for 50 PSF

← Older revision		Revision as of 01:31, 9 November 2025
Line 23:		Line 23:
	*32' truss - 16' reinforcement on mid of 6' supported 32' truss still works for 50 psf! [https://chatgpt.com/share/6875ac72-d4a4-8010-9b88-122dc2123679]		*32' truss - 16' reinforcement on mid of 6' supported 32' truss still works for 50 psf! [https://chatgpt.com/share/6875ac72-d4a4-8010-9b88-122dc2123679]
	*24' truss - with 16' span, works at 50 psf [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]. Note for 16' walls - we have 15' span actually when using 2x6 lumber - and SPF #2 orks, while 16' fails by 8%.		*24' truss - with 16' span, works at 50 psf [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]. Note for 16' walls - we have 15' span actually when using 2x6 lumber - and SPF #2 orks, while 16' fails by 8%.
	*24' truss - with 20' span - needs 16' reinforcement - [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]		*{{Check}}24' truss - with 20' span - needs 16' reinforcement - [https://chatgpt.com/share/6875a47e-ba7c-8010-a839-ebedc61da942]. '''This is the design we are using for the [[Hangar]] to achieve a 32' clear section in the middle: 20' effective span + 6' support on each side. The supporting trusses are 16' long - 2' overhang of roof - 8' over side rooms - and 6' supporting section in the middle. With a telehandler - 5 of the 52' long trusses can be bound together with roof OSB, rim boards, and soffit - and lifted in 52'x8' modules.
	*24' truss - with 23' span - needs -		*24' truss - with 23' span - needs -

Marcin at 01:25, 9 November 2025

2025-11-09T01:25:32Z

← Older revision		Revision as of 01:25, 9 November 2025
Line 1:		Line 1:
	{{Hint\|This is shear and bottom chord tension calculations for flat trusses resembing standard [[I-Joists]] - OSB web with bottom and top chords. We are ending up with 24' long, 1/2"x16" tall OSB web trusses with 2x4s as the upper and lower chord. Design value of 425 psi tension is used for SPF #2 lumber. We have not heard of 32' spans accomplished with 24" centers for 50 PSF roof or floor loading. The trick is using auxiliary trusses on the side, such that auxiliary trusses supported by walls extend 6' past the wall, join to the 24' main truss starting at the 4' mark, and overlap the main truss for 2 feet for safe connection. This converts the 24' main truss into an effective 20' span, while overall span including auxiliary trusses is 32' with a 50 psf rating. A secondary 2x4 lumber stick, 16' long, reinforces the bottom chord over the middle section (any longer does not help for the design specification). Please email us at info at opensourceecology dot org with Truss Calculations in the subject line if you see any corrections to the model below. The bottom line is '''4x lower material cost''' and '''2x material use efficiency''' improvement due to 24" on center spacing instead of the typical case of i-joists, which have geometry unsuitable for end to end overlap. 8x cost improvement compared to industry standards.}}		{{Hint\|This is shear and bottom chord tension calculations for flat trusses resembing standard [[I-Joists]] - OSB web with bottom and top chords. We are ending up with 24' long, 1/2"x16" tall OSB web trusses with 2x4s as the upper and lower chord. Design value of 425 psi tension is used for SPF #2 lumber. We have not heard of 32' spans accomplished with 24" centers for 50 PSF roof or floor loading. The trick is using auxiliary trusses on the side, such that auxiliary trusses supported by walls extend 6' past the wall, join to the 24' main truss starting at the 4' mark, and overlap the main truss for 2 feet for safe connection. This converts the 24' main truss into an effective 20' span, while overall span including auxiliary trusses is 32' with a 50 psf rating. A secondary 2x4 lumber stick, 16' long, reinforces the bottom chord over the middle section (any longer does not help for the design specification). Please email us at info at opensourceecology dot org with Truss Calculations in the subject line if you see any corrections to the model below. The bottom line is '''4x lower material cost''' and '''2x material use efficiency''' improvement due to 24" on center spacing instead of the typical case of i-joists, which have geometry unsuitable for end to end overlap. '''This results in 8x cost improvement compared to industry standards.'''}}

Marcin at 07:56, 21 July 2025

2025-07-21T07:56:18Z

← Older revision		Revision as of 07:56, 21 July 2025
Line 1:		Line 1:
	{{Hint\|This is shear and bottom chord tension calculations for flat trusses resembing standard [[I-Joists]] - OSB web with bottom and top chords. We are ending up with 24' long, 1/2"x16" tall OSB web trusses with 2x4s as the upper and lower chord. Design value of 425 psi tension is used for SPF #2 lumber. We have not heard of 32' spans accomplished with 24" centers for 50 PSF roof or floor loading. The trick is using auxiliary trusses on the side, such that auxiliary trusses supported by walls extend 6' past the wall, join to the 24' main truss starting at the 4' mark, and overlap the main truss for 2 feet for safe connection. This converts the 24' main truss into an effective 20' span, while overall span including auxiliary trusses is 32' with a 50 psf rating. A secondary 2x4 lumber stick, 16' long, reinforces the bottom chord over the middle section (any longer does not help for the design specification). Please email us at info at opensourceecology dot org with Truss Calculations in the subject line if you see any corrections to the model below.}}		{{Hint\|This is shear and bottom chord tension calculations for flat trusses resembing standard [[I-Joists]] - OSB web with bottom and top chords. We are ending up with 24' long, 1/2"x16" tall OSB web trusses with 2x4s as the upper and lower chord. Design value of 425 psi tension is used for SPF #2 lumber. We have not heard of 32' spans accomplished with 24" centers for 50 PSF roof or floor loading. The trick is using auxiliary trusses on the side, such that auxiliary trusses supported by walls extend 6' past the wall, join to the 24' main truss starting at the 4' mark, and overlap the main truss for 2 feet for safe connection. This converts the 24' main truss into an effective 20' span, while overall span including auxiliary trusses is 32' with a 50 psf rating. A secondary 2x4 lumber stick, 16' long, reinforces the bottom chord over the middle section (any longer does not help for the design specification). Please email us at info at opensourceecology dot org with Truss Calculations in the subject line if you see any corrections to the model below. The bottom line is '''4x lower material cost''' and '''2x material use efficiency''' improvement due to 24" on center spacing instead of the typical case of i-joists, which have geometry unsuitable for end to end overlap. 8x cost improvement compared to industry standards.}}