Roof ventilation Ottawa — Guns N' Hoses Roofing
Guns N' Hoses Roofing Ottawa

ROOF VENTILATION
& ICE DAM PREVENTION
IN OTTAWA

Most roofers install shingles. Few understand the science beneath them. Guns N' Hoses is Ottawa's only Ventilation Maximum certified roofing contractor — we stop ice dams, attic moisture, and premature roof failure at the source.

Ottawa's only Ventilation Maximum certified roofing contractor. Free assessments available.

VM
Certified
13+
Years in Ottawa
500+
Ottawa Roofs Done
Ventilation Maximum Certified

The Only Ottawa Roofer With
Ventilation Maximum Certification

Guns N' Hoses is one of very few Ottawa roofing contractors certified by Ventilation Maximum — the industry standard for residential roof ventilation design and installation.

This certification means Vanessa has been trained and tested on attic airflow science, moisture control, and Ottawa-specific climate demands. It is not a badge any roofer can buy.

Why Roof Ventilation Is
Critical in Ottawa

Ottawa's climate makes ventilation more important than in most Canadian cities. The combination of heavy snowfall, extreme cold, and rapid spring thaws creates conditions that punish poorly ventilated roofs every single year.

A properly ventilated roof keeps the attic temperature regulated — cold enough in winter to prevent snow from melting prematurely at the roof surface, and cool enough in summer to protect shingles from heat damage. Without that balance, homeowners face ice dams, mold, and roofs that fail 10 years before they should.

Under-Ventilated Roof

The attic traps heat. Snow on the roof melts from below, runs down to the cold eave overhang, and refreezes as ice. This cycle builds ice dams. When spring arrives, pooled water backs up under shingles and enters the home. Under-ventilation is the leading cause of roof leaks in Ottawa.

Over-Ventilated Roof

Too much airflow makes the attic too cold. Frost forms on the underside of the roof deck. When it melts in spring, it soaks insulation, promotes mold, and can cause water damage to drywall, electrical systems, and framing — all from the inside.

Correctly Ventilated Roof

Balanced intake and exhaust keeps attic temperature within 10–20°C of outside temperature year-round. No ice dams. No frost buildup. Shingles last their full rated lifespan. Heating and cooling bills stay lower. This is what we design.

How to Read Your
Attic Temperature

Your attic temperature should track the outside temperature within a 10–20°C range year round. Here is what to look for:

Season Outside Temp Target Attic Temp
Summer 35°C – 36°C 65°C – 71°C maximum
Winter Varies by set temp Never below 15°C below outside

If attic temperatures fall outside these ranges, you have a ventilation problem. Temperatures over 54°C in summer indicate inadequate exhaust ventilation and will accelerate shingle deterioration and risk mold and ice damming.

Not comfortable going into your attic? That is what a Guns N' Hoses ventilation assessment is for. We take the readings, interpret them, and tell you exactly what your roof system needs — no guesswork.

How Ice Dams Form —
and Why They Cause Spring Leaks

Most Ottawa homeowners think ice dams are a winter problem. They are actually a spring problem caused by winter conditions. Here is the sequence:

1

Heat escapes through the roof deck due to poor ventilation or inadequate insulation.

2

Snow on the upper roof melts from below and flows downward.

3

Water reaches the cold eave overhang — where there is no heat loss — and refreezes into a solid ice dam.

4

More snowmelt flows down and hits the ice dam. With nowhere to go, it pools behind the dam.

5

Pooled water backs up under shingles. Even a 2mm gap is enough for water to enter the roof structure.

6

Spring arrives. The ice dam melts. The homeowner discovers water stains, damaged insulation, or active dripping — and has no idea it started in January.

The fix is never just removing the ice dam. The fix is correcting the ventilation conditions that created it. That is what Guns N' Hoses assesses and addresses.

Signs Your Ottawa Roof Has
a Ventilation Problem

Icicles forming at the eaves every winter.

Ice dams building up along the roof edge.

Your roof shows bare shingles while neighbours have snow — heat loss pattern. Vertical columns of bare shingles are a clear warning sign.

Water stains on the ceiling in spring with no obvious cause during winter.

Mold or frost on the underside of the roof deck.

The second floor of your home is noticeably colder than the main floor in winter.

Shingles deteriorating faster than expected for their age.

Higher than expected heating bills with no other cause.

If you checked any of these, a ventilation assessment will tell you exactly what is wrong and what it will cost to fix it.

What Guns N' Hoses Checks
During a Ventilation Assessment

01

Step 1 — Attic Inspection

We enter the attic and take temperature and moisture readings. We inspect insulation depth and placement, existing vent positions, and any signs of frost, mold, or moisture damage.

02

Step 2 — Intake & Exhaust Calculation

We calculate the current airflow balance — how much air is entering through soffit vents versus how much is exhausting through ridge or roof vents. Imbalance in either direction causes problems.

03

Step 3 — Problem Identification

We identify exactly what is wrong and why — blocked soffits, inadequate ridge venting, missing baffles, or insulation covering intake vents are the most common Ottawa findings.

04

Step 4 — Written Recommendations

You receive a clear written summary of what your roof system needs, why, and what it will cost. No pressure to proceed — but everything you need to make an informed decision.

Ventilation & Ice Dam Questions
Ottawa Homeowners Ask Us

Can I prevent ice dams without replacing my roof?
Often yes. In many Ottawa homes, ice dams are caused by ventilation or insulation problems that can be corrected without a full replacement. We assess the root cause first and recommend the least invasive fix that actually solves the problem.
My neighbour has ice dams every year and does nothing. Why should I worry?
Ice dams themselves do not always cause immediate damage. The damage happens when pooled water finds a gap to enter through — and that gap may not show symptoms until spring, or until years of moisture have rotted the sheathing beneath. The risk is silent until it is expensive.
Does adding more vents always fix the problem?
No — and this is where many Ottawa roofers cause more problems than they solve. Adding exhaust vents without matching intake creates negative pressure that pulls conditioned air from the house into the attic. The system needs to be balanced, not just enlarged. This is exactly what Ventilation Maximum certification trains for.
How much does a ventilation assessment cost?
Contact us for current pricing. In most cases the cost of an assessment is applied toward any work we perform as a result of the findings.
Will improving my ventilation lower my heating bills?
Yes, in most Ottawa homes. Heat loss through a poorly ventilated attic is one of the most common and correctable causes of high winter heating bills. Better ventilation keeps heat where it belongs — inside your home.

What Ottawa Homeowners
Say

“Vanessa and her team did my parents' roof a few months back. She was very quick to respond and communication was great. She had a lot of patience explaining things to my parents as they don't speak English very well.”

— Jenn, South Keys, Ottawa

“I would highly recommend. We had a leak in our roof and Vanessa and her team were able to fix the issue in a timely manner. We will be using her services again.”

— Sunny, Gloucester

Book a Ventilation
Assessment in Ottawa

We take the readings, interpret them, and tell you exactly what your roof system needs. No guesswork, no pressure.

Call Vanessa Directly

613-801-8582

Send Us an Email

info@gunsnhosesroofing.ca

Service Area

Ottawa · Nepean · Kanata · Stittsville · Gloucester · Orleans

Hours

Mon – Fri

7:00 AM – 6:00 PM

Sat – Sun

By Appointment

Request a Free Ventilation Assessment

We cover all of Ottawa. We'll be in touch within 24 hours.

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ROOFING
Don't Wait Until It Leaks

YOUR ROOF IS YOUR FIRST LINE OF DEFENSE

Every day you delay could mean more damage, more cost, more risk. Let Ottawa's most trusted roofing team give you peace of mind — starting with a free inspection.