HomeMy WebLinkAbout9908-175 Revised Attic Ventilation Calculations6
09/08/1999 14:06 909-784-0844
STEVEN
HOMES
PAGE 01
STEVEN WALKE
909/784-0840
Fax - Memo - T
To: City of La Quinta Bldg & Safety Ann: Mark F
Frpm: Chuck Frase Dabe: 09/08/9
Re: Pool Building -- Ryder at Merion Pages:
Fax: 760/777-7011 CC:
HOMES
fax
mittal
51
LI U gent X For Review ❑ PWase Comment ❑ Flue R90y [] Please Awycie
Derar Main,
Here is a copy of the revised Attic vratt hmon caicuiatlons vole ab0W this day. I have used the /
same rAdO from the approved plans for the vent iMion mquimd. Hope the resglves the tissue and wie V
can aQ put thts bd*w us. D
Thanks again for aY your Assistshce k is a pleasure to do bLWrwm me vorr dwartrnm*
Chuck Frase
Direr Of 010erahOns - StVn Wakes Homes
80W784-084
fax - Me=-TOWWrOd Clty Of La 00b Marls NO Bldg & Sdy 0"848
09/08/1999 14:06
THE--O'H
909-784-0844 STEVEN WALKER HOMES PAGE 02
1. r -U;e
E
JnTm VEWTILATJO
BASIC BUILDING CODE REQUIREMENTS
FOR ATTIC VENTILATION
MINIMUM 11300
One square foot of NFVA for each 300 square foot of area to be
venhioted provided o vapor barrier is used, or 5ffo of NFVA is
located at eaves and roof vents are at least 3 feet or more above
eove vents.
BETTER 1/150 (one to one rule)
When minimum requirements above are riot met -code
requirements are doubled to one square float of each NFVA far
each 150 square feet of area to be ventilated_
SUPERIOR 1/100 (one percent rule)
Superior ventilation requires continuous ridge ventilation the
entire length of the roof with matching lengths of vent in eave,
SQUARE INCITES OF
NET FREE VENT AREA IIVFVAI
j MINIMUM 1/300 for 1000 square feet
240 inches of ridge vent 50% required
240 inches of eave vent 50% required
BETTER 1/150 for 1000 square feet
480 inches of ridge vent 50% required
480 inches of eave vent 5G% required
SUPERIOR 1/100 for 1000 square feet
576 inches of ridge vent40% required
864 inches of eave vent 60% required
8"ved"Y
vest
FSTEM
f Vat "v
peers Villa style roof vent
Ea urat (primary and secondary
vent co biped) equals 95 sq inches NFVA
An eave to ridge ventilation system creates a continuous
circulation of air flow naturally with external air flow arruss the
roof. A vacuum or venturi effect draws the air in through the
eave vents ford air out through the ridge vents_ When there
is no wind the vi mfilation, occurs naturally. As warm air rises it
is exhausted through the ridge vents drawing fresh air in
through the eave vents,
When installing he foil ventilation system using the O'Hogin'"
Cloaked Vent Til , the best placement is one course from the
ridge (allowing r short course) and a course up post the wall
line at the eave. This will create the best possible airflow with
no expensive po led vents and no obhusive typo of dormer
vents.
This continuous natural dreulalion of air is ifre Key to heading
off venting probl,,ms in the building. Use the handy table
shown to calcula a the requirements for your needs.
CALCULATION TABLE FOR VENTILATION KEQUIREMENTS USI
SQUARE FEET
UNITS FOR
RULE
I/300
qa% ridge
50% eave
1 /1"
50% ridge
50% eave
1 / 1410
40% ridge
60% eave
1000 10+00 2000 2500 3000
O'NAGIN CLOAKED VENT TILE
4000 4500 5000
2 6
7
8
9
1
11
12
13
3 6
7
a
9
1
It
12
13
5 8
10
13
15
18
20
23
26
5 8
10
13
15
1
20
23
26
6 9
12
1S
IN
2
25
28
31
9 14
18
23
27
3
36
41
46
PI TIONE (1-800-394-3864 or 1- 707-823.4762) or FAX (1 `707-523-5208) FOR ORE INFORMA1'lON TC)DAY j
09/08/1999 14:06 909-784-0844 STEVEN WALKER HOMES
PAGE 03
Attu Ventilation Calculations Worksheet - Ryder Collection - PQA West, La Quanta, CA
Plan 1 A & B Total ventilation required 2681 s.f. / 3 00 .l34 s.f.
O'Hagin Roof vents 0.66 s.f. per vent
# ea. 14
--44".aU%Pjw j UVIUUU .24 s.f.
1 C Total ventilation required 2681 s.f. / 300 .94 s,f.
O'Hagin Roof vents 0_66 s.f. per vent
# ea. 9
Gable end vents 1.50 s.f. per vent ( 2 X 24 )
# ea, 2
Ventilation provided d... ;
2 A & B Total ventilation required 2999 s.f. / 3o0 10LOO s.f.
O'F{agin Roof vents
0.66 s.f.
per vent
# ea.
16
Ventilation Provided
10,56
s.f.
2 C Total ventilation required 2M s.f_
/ 300
10
00 s,f.
O'Hagin Roof vents
0.66 s.f.
per vent
# ea.
9
Gable end vents
1.50 s.f.
per vent
(1
X 24 )
# ea.
3
Ventilation provided
10
s.f.
I A & B Total ventilation required 2942 s.f.
/ 300
9.
1 s.f.
O'Hagin Roof vents
0.66 s,f,
per vent
# ea,
15
Ventilation provided
s
RID r f
enwanon required 2942 s.f. / 300 9.111 s.f..
O'Hagin Roof vents 0.66 s.f. per vent
# ea_ 7
Gable end vents 1.75 s.f. per vent ( 14 X 24 )
# ea. 3
mtllation provided 9. 7 s,f.
Attic VerrtiiaW wksht 04-0e .As