Application Instructions

IKO

Cambridge™ Shingles | Application Instructions | English | PAGE 1 OF 7

ENGLISH

IMPORTANT MESSAGE • PLEASE READ! IKO assumes no responsibility for leaks or

defects resulting from improperly installed shingles, improper preparation of the

surface to be roofed over, or failing to provide proper ventilation in accordance with

local building codes. Use caution when stacking bundles on sloped roofs.

ROOF SLOPE / ROOF DECKS: Never apply asphalt shingles to roof slopes less than 2:12. For

slopes 2:12 to less than 4:12 (LOW SLOPE), see special underlayment requirements outlined

below. We do not recommend the application of our roof shingles directly to any type of roof

insulation, including perlite or ﬁberglass, foam, wood ﬁber, or similar products. Further, the

application of our rooﬁng shingles directly over any structural decks including gypsum, nailable

concrete, or similar products (without our prior approval) will void the warranty.

IKO

Cambridge™ Shingles | Application Instructions | English | PAGE 2 OF 7

STEP 1:

PREPARE THE ROOF DECK: Deck must be smooth,

ﬁrm, clean, dry and securely nailed. Wood panel decking

is to be exterior grade, conforming to building code

requirements. Panels are to be 3/8″ min. thick plywood,

or 7/16″ min. thick non-veneer. The installation of asphalt

shingles on dimensional lumber (including shiplap/

board decks) is not recommended as it may potentially

cause buckling problems, which are not covered by IKO’s

Limited Warranty.

STEP 2:

APPLY DRIP EDGE ALONG EAVES: Apply metal drip

edge over underlayment or directly to the deck along the

eaves, spacing nails approximately 12” apart, conforming

to building code requirements.

STEP 3:

EAVE PROTECTION: Apply eave protection, such as

IKO StormShield

Ice & Water Protector, as per building

code requirements and manufacturer’s instructions,

overhanging eaves by 1/4” to 3/4” and extending up

the roof at least 24” beyond the vertical projection

of the interior surface of the outside wall. NOTE: IKO

recommends the use of eave protection in all situations,

however, if no ice and water protector is required by your

local code or standard, then alternately apply ﬁrst course

of underlayment overhanging the eaves by 1/4” to 3/4”.

STEPS 1-3

Roof Deck

Ice & Water Protector

Metal Drip Edge

IKO

Cambridge™ Shingles | Application Instructions | English | PAGE 3 OF 7

STEP 4:

UNDERLAYMENT: Apply either asphalt saturated felt or

synthetic underlayment, such as IKO’s Stormtite™, in

horizontal courses up the roof with 2” side laps and 4” end

laps. Trim the sheet to ﬁt the ﬁnal course at the peak. One

layer of underlayment is required over the entire deck to

qualify for an ASTM E108/UL790 Class A ﬁre-resistance

rating or which may be required per the local building code.

LOW SLOPE: For roof slopes less than 4:12 down to 2:12

apply underlayment in successive courses by overlapping

the preceding sheet by 19” with 4” end laps. Alternatively,

apply a single layer of ice and water protector over the

entire deck per manufacturer’s instructions.

NOTE: SHINGLES APPLIED ACCORDING TO THESE

INSTRUCTIONS ON SLOPES 3:12 TO 4:12 WILL BE

WARRANTED FOR THE FULL WARRANTY TERM.

SHINGLES ON SLOPES LESS THAN 3:12 DOWN TO 2:12

WILL BE WARRANTED FOR 12 YEARS.

STEP 5:

APPLY DRIP EDGE AT THE RAKES: Apply metal drip

edge on top of any underlayment along rake edges,

spacing nails approximately 12” apart.

STEPS 4-5

Metal Drip Edge

Underlayment

IKO

Cambridge™ Shingles | Application Instructions | English | PAGE 4 OF 7

STEP 6:

INSTALL FLASHING: Corrosion-resistant ﬂashing must

be used to help prevent leaks where a roof meets a wall,

another roof, a chimney or other objects that penetrate

a roof. Flashing shall conform to the requirements of

applicable building code and good rooﬁng practice.

STEP 7:

INSTALL OPEN METAL VALLEYS: Metal valleys are

recommended. (Closed valley applications are acceptable

but not recommended. Please see Limited Warranty

for details.) Complete valley ﬂashing before shingles

are applied. Center a 36” wide strip of ice and water

protector in the valley and then fasten at the edges with

only enough nails to hold in place. Center a minimum

24” wide, minimum 28 gauge pre-ﬁnished/galvanized

metal valley liner in the valley, and fasten the edges

with only enough nails to hold in place. Snap two chalk

lines the full length of the valley, 6” apart at the top and

increasing in width 1/8” per foot towards the bottom.

When the shingles are being applied, lay them over the

valley ﬂashing, trim the ends to the chalk line, and cut a

2” triangle off the corner to direct water into the valley

(A). Embed the valley end of each shingle into a 3” band

of asphalt plastic cement (B). Do not place a nail in the

shingle closer than 2” from the chalk line.

STEPS 6-7

Metal Flashing

Ice & Water Protector

Chalk Lines

IKO

Cambridge™ Shingles | Application Instructions | English | PAGE 5 OF 7

STEP 8:

INSTALL STARTER COURSE: IKO recommends using

Leading Edge Plus™ Starter Shingles. Fold the Leading

Edge Plus shingle along the perforation to separate.

Cut the ﬁrst starter shingle in half. Beginning at the left

corner of the roof, start the eaves course by positioning

one of the halves granule side up with the sealant

adjacent to the eaves. It should overhang the eaves and

rake edge by 1/4” to 3/4”. Start the rake course by taking

the remaining half and positioning it ﬂush to the top

edge of the eaves starter with the sealant adjacent to

the rake edge overhanging the rake edge by 1/4” to 3/4”.

Fasten the half-length shingles with nails located about

3” from the eaves edge and 1” in from each end with a

third in the center. Complete the eave and rake starter

courses with full lengths of starter shingles maintaining

a 1/4” to 3/4” overhang, and fastening with four nails per

shingle. Alternatively, apply IKO EdgeSeal as directed by

EdgeSeal application instructions.

STEP 9:

INSTALL THE FIRST COURSE: Start with a full length

shingle applied ﬂush with starter course at rake and eave.

Use four nails per shingle placed as shown below. After

the ﬁrst shingle in the course is installed, continue with

full length shingles to complete the ﬁrst course, trimming

the last shingle so that it matches the overhang of the

starter course below.

STEP 8

Starter Course

STEPS 9-13

Trim

30"

20"

10"

Shingle Courses

Starter Course

Fourth Course

First Course

Second Course

Third Course

IKO

Cambridge™ Shingles | Application Instructions | English | PAGE 6 OF 7

PROPER NAILING:

NAILING ON STEEP SLOPES/HIGH WIND AREAS: For

high wind areas or on slopes of 21:12 (60°) or more, use six

nails per shingle placed as shown above. Ensure that no

nail is within 2” of a joint/cutout of the underlying shingle.

Seal down each shingle at time of application with three

1” diameter spots of rooﬁng cement placed under the

shingle 2” above the bottom edge and equally spaced

along the shingle. Use rooﬁng cement sparingly, as

excessive amounts may cause blistering.

STEP 10:

CHALK LINES: To aid in alignment, snap horizontal

chalk lines. Cambridge exposure is 5-7/8″.

STEP 11:

INSTALL THE SECOND, THIRD AND FOURTH COURSES:

Trim off 10″, 20″, and 30″ respectively, from the left end

of the starting shingle and apply to overhang rake edge

by 1/4″ to 3/4″. Continue each course across the roof with

full shingles butting ends loosely. Align the bottom

edge of the shingles with the tops of the saw teeth of

the shingles in the underlying course. Note: Other offsets

between 6″ – 10″ may be used. These alternative offsets

will not adversely affect the applicable provisions of

IKO’s Limited Warranty, but may in some instances

result in aesthetic issues.

STEP 12:

INSTALL THE FIFTH AND SUCCEEDING COURSES:

Repeat the sequence of the ﬁrst four courses up the

roof. For maximum wind protection, cement shingles

at rake edges.

IMPORTANT! — PROPER NAILING

Nail Line

578" EXPOSURE

Common Bond

Standard Application

Requires 4 Nails

Steep Slope/High Wind Applications

Requires 6 Nails

Nail

Line

Apply Rooﬁng Cement CAUTION: Excessive

Use of Rooﬁng Cement Can Cause Shingles to Blister.

7/8"

Nail

Line

578"

IKO

Cambridge™ Shingles | Application Instructions | English | PAGE 7 OF 7

STEP 13:

MANUALLY SEAL SHINGLES (IF NEEDED): Shingles

should seal to the underlying course when the factory

applied asphalt sealant is sufﬁciently warmed by the heat

of direct sunlight. When conditions such as cool weather,

high winds or blowing dust might limit the effectiveness

of the sealing strip, please follow the manual sealing

instructions found in the Nailing on Steep Slopes/High

Wind Areas section above.

STEP 14:

INSTALL HIPS AND RIDGES: IKO recommends its pre-cut

Hip and Ridge products, or pre-formed high proﬁle IKO

UltraHP. For IKO pre-cut Hip and Ridge products bend

each piece over the hip or ridge, and nail per instructions

on the wrapper. The exposed nail heads of the ﬁnal

shingle should be covered with rooﬁng cement. For

IKO UltraHP, follow the instructions on the box. Prior to

application in cold weather, store hip and ridge shingles

in a heated area to allow for easier bending.

IMPORTANT MESSAGE • PLEASE READ!

To ensure coverage under the High Wind Resistance Limited Warranty: Starter strip shingles must be used at all eaves

and rakes. The shingles must be installed with additional nails as speciﬁed, and they must have an opportunity to seal

or be manually sealed as described. In Canada, manual sealing in addition to 6 nails is required. In Florida, manual

sealing is not required.

IMPORTANT: FOR ALL APPLICATIONS IT IS CRITICAL TO USE THE NAIL LINE AS A GUIDE. HIGH NAILING ABOVE THE

NAIL LINE CAN VOID IKO’S LIMITED WARRANTY.

FASTENERS: Nails must be 11 or 12-gauge rooﬁng nails, corrosion-resistant, with at least 3/8″ heads, and at least 1″ long.

For decks 3/4″ thick or thicker, nails must go at least 3/4″ into the deck. On thinner decks, nails must go at least 1/8″

through the deck.

3/8" Min.

Diameter

Overdriven CrookedUnderdriven

Perfectly

Nailed

Roof Deck

Asphalt Shingles