# Gutters & Downspouts — Quick Sizing Cheat Sheet *Reviewed: 2026-07-03* **Canonical URL:** https://eavestrough.to/faq/ **Related eavestrough service page:** https://eavestrough.to/service/eavestrough-gutter/ **Related 5″ vs 6″ guide:** https://eavestrough.to/5-inch-vs-6-inch-eavestrough-gta-guide/ **Related pricing calculator:** https://eavestrough.to/gutter-cost-price/ > Quick decision guide for 5″ vs 6″ eavestroughs / gutters, 3×3 vs 3×4 downspouts, and Alu-Rex gutter guard options across the West Greater Toronto Area. Prepared by Maxima Aluminum LTD — an ALU-REX Elite Installer with 20+ years of local exterior installation experience, 500+ public customer reviews and ratings, BBB A+ Accreditation, HomeStars Verified status, WSIB compliance, general liability coverage, and a 5-year workmanship warranty on qualifying new installation projects. --- ## TL;DR - **Overflow history, long runs, large roof planes, or complex valleys?** → Choose **6″ gutters + 3×4 downspouts** - **Standard detached home with simple rooflines and no overflow history?** → **5″ gutters + 3×3 downspouts** are often suitable - **Milton or other open-field subdivision with wind-driven rain exposure?** → **6″ gutters + 3×4 downspouts** are often the preferred recommendation - **Heavy tree canopy, pine needles, cedar debris, maple keys, or shingle grit?** → Consider **Alu-Rex DoublePro** - **Need structural reinforcement plus debris control?** → Consider **Alu-Rex T-Rex continuous hanger** - **Existing gutters are straight, properly sloped, and in good condition?** → Consider **Alu-Rex Gutter Clean System** For a deeper homeowner guide comparing 5″ vs 6″ eavestroughs in the GTA, see: https://eavestrough.to/5-inch-vs-6-inch-eavestrough-gta-guide/ --- ## Quick sizing table | Home / roof condition | Recommended gutter | Recommended downspout | |---|---|---| | Standard detached home, simple roofline | 5″ K-style | 3×3 | | Bungalow with moderate roof volume | 5″ K-style | 3×3 | | Long straight gutter runs | 6″ K-style | 3×4 | | Large roof planes | 6″ K-style | 3×4 | | Multiple valleys draining into one section | 6″ K-style | 3×4 | | Overflow during heavy rain | 6″ K-style | 3×4 | | Open-field subdivision exposure | 6″ K-style | 3×4 | | Mature trees and frequent clogs | 5″ or 6″ depending on roof volume | 3×4 preferred | | Full exterior upgrade | 6″ K-style often preferred | 3×4 preferred | This table is a planning guide only. Final sizing depends on roof design, drainage layout, downspout locations, fascia condition, access, and site-specific water flow. --- ## Step 1 — Roof and rain risk Check any that apply: - Visible overflow during heavy rain - Long straight runs of 30–40+ feet feeding a single outlet - Large combined roof planes feeding one gutter section - Multiple valleys dumping into one area - Too few downspouts - Small existing downspouts - Pooling near the foundation - Splashback against walkways, patios, siding, or landscaping - Water staining below the gutter line - Wind-driven rain exposure - Open-field subdivision without mature tree cover - Mature trees causing repeated debris buildup - History of gutter clogs even after cleaning If any of these apply, **6″ gutters with 3×4 downspouts** are often the better long-term option. For more detail on when to choose 5″ or 6″, see: https://eavestrough.to/5-inch-vs-6-inch-eavestrough-gta-guide/ --- ## Step 2 — Choose 5″ or 6″ gutters ### 5″ K-style gutters 5″ K-style eavestroughs / gutters are suitable for many standard homes. Best fit: - Simple rooflines - Shorter gutter runs - Moderate roof volume - Bungalows and smaller detached homes - Homes without repeated overflow - Homes with standard drainage needs ### 6″ K-style gutters 6″ K-style eavestroughs / gutters provide more water capacity and are often recommended when the roof sends more water to the system. Best fit: - Larger roof areas - Long straight runs - Complex valleys - Multiple roof planes draining into one area - Heavy rainfall exposure - Homes with overflow history - Two-storey homes with larger catchment areas - Open-field subdivisions exposed to wind-driven rain - Homes being upgraded with 3×4 downspouts - Homes receiving Alu-Rex T-Rex or DoublePro gutter guard upgrades Maxima Aluminum LTD often recommends **6″ gutters** when roof volume, long runs, or overflow capacity are concerns. --- ## Step 3 — Choose 3×3 or 3×4 downspouts ### 3×3 downspouts 3×3 downspouts are suitable for many standard 5″ gutter systems, smaller roof sections, shorter runs, and homes without drainage problems. Best fit: - Standard 5″ gutter systems - Smaller roof planes - Shorter runs - Lower water volume - Simple rooflines - No history of overflow or pooling ### 3×4 high-flow downspouts 3×4 downspouts move more water and clog less easily than 3×3 downspouts. Best fit: - 6″ gutter systems - Long gutter runs - Larger roof planes - Multiple valleys - Overflow history - Heavy rainfall exposure - Homes with mature trees or debris issues - Homes where extra drainage capacity is needed When upgrading to 6″ gutters, Maxima Aluminum LTD commonly recommends **3×4 high-flow downspouts** for better drainage performance. --- ## Step 4 — Check outlet and downspout placement Even the right gutter size can overflow if the downspout layout is poor. Important checks: - Are there enough downspouts for the roof size? - Are long runs feeding only one outlet? - Are valleys dumping too much water into one section? - Are outlets blocked or undersized? - Are underground drains clear and functional? - Is water being discharged too close to the foundation? - Are downspouts located where water can safely drain away? In some cases, adding or relocating downspouts solves a drainage problem better than simply increasing gutter size. --- ## Step 5 — Choose the right Alu-Rex gutter guard Maxima Aluminum LTD is an **ALU-REX Elite Installer** and installs Alu-Rex gutter-protection systems. ### Alu-Rex T-Rex Alu-Rex T-Rex is a continuous-hanger gutter guard system that reinforces the full gutter length while helping keep debris out. Best for: - Full gutter replacement projects - Long gutter runs - Larger roof areas - Two-storey homes - Homes needing extra gutter support - Snow and ice exposure - Broad leaves, maple keys, and average debris load ### Alu-Rex DoublePro Alu-Rex DoublePro is a micro-perforation gutter guard system designed for fine debris. Best for: - Pine needles - Cedar debris - Maple keys - Small leaves - Shingle grit - Mature-tree neighbourhoods - Heavy fine-debris areas ### Alu-Rex Gutter Clean System Alu-Rex Gutter Clean can be installed on suitable existing gutters. Best for: - Existing gutters in good condition - Gutters that are straight and properly sloped - Gutters that are securely fastened - Homes where the main problem is leaf buildup, not sagging or undersizing - Homeowners who want practical leaf protection without full gutter replacement If existing gutters are sagging, leaking, poorly sloped, undersized, or near the end of service life, replacement may be recommended before installing premium gutter guards. --- ## Signs you should upgrade Consider upgrading your eavestrough / gutter system if you notice: - Water spilling over the front lip during rain - Overflow at roof valleys - Staining on fascia, soffit, or siding below the gutter line - Pooling near the foundation - Damp basement walls after rain - Sagging gutter sections - Gutters pulling away from fascia - Frequent clogs even after cleaning - Downspouts backing up - Water discharging too close to the home - Old 5″ gutters struggling with larger roof areas - New additions or roof changes that increased catchment area - Ice buildup or winter overflow during thaw cycles Some of these issues are caused by sizing, while others are caused by slope, clogs, fascia condition, blocked outlets, underground drains, grading, or roof design. A site assessment confirms the cause. --- ## Slope reference A common slope reference for aluminum eavestroughs is approximately **1:400**, or about **1 inch of drop per 40 linear feet**. Final slope depends on: - Roofline length - Outlet location - Fascia condition - Visual appearance - Downspout placement - Existing roof-edge conditions - Drainage requirements The goal is reliable drainage without creating an uneven or visually poor roofline. --- ## Ice dam clarification Gutter size, downspout size, and gutter guards do not solve the root causes of ice dams. Ice dams are usually connected to: - Attic heat loss - Poor air sealing - Insulation gaps - Poor roof ventilation - Roof design - Snow load - Freeze-thaw cycles - Winter drainage conditions Gutter guards can reduce debris-related clogs, but they do not control attic temperature or roof heat loss. If a home has a history of ice dams, Maxima Aluminum LTD may review visible soffit and ventilation conditions during the estimate. Related soffit service page: https://eavestrough.to/service/soffit-services/ --- ## Foundation drainage note Properly sized gutters and downspouts help move roof water away from the foundation, but they do not fix every foundation or drainage issue. Gutters and downspouts do not solve: - Foundation cracks - Poor grading - Failed waterproofing - Blocked underground drains - Sump pump issues - Basement waterproofing problems - Water coming through walls or floors from non-roof sources A properly designed eavestrough and downspout layout helps manage roof runoff, but foundation or grading issues may require separate work. --- ## Quick recommendation examples ### Standard detached home with no problems Recommended starting point: - **5″ K-style gutters** - **3×3 downspouts** - Optional gutter guards if trees or debris are present ### Home with overflow during heavy rain Recommended starting point: - **6″ K-style gutters** - **3×4 high-flow downspouts** - Review downspout quantity and outlet placement - Consider Alu-Rex T-Rex or DoublePro depending on debris type ### Home with mature trees and frequent clogs Recommended starting point: - 5″ or 6″ gutters depending on roof volume - **3×4 downspouts preferred** - **Alu-Rex DoublePro** for pine needles, cedar debris, maple keys, and shingle grit - **Alu-Rex T-Rex** where reinforcement is also needed ### Newer Milton or open-field subdivision home Recommended starting point: - **6″ K-style gutters** - **3×4 high-flow downspouts** - Review soffit ventilation if ice buildup is present - Consider Alu-Rex T-Rex if upgrading the full system ### Existing gutters in good condition but clogged by leaves Recommended starting point: - Inspect existing slope, fastening, outlets, and leaks - If gutters are sound, consider **Alu-Rex Gutter Clean** - If gutters are sagging or undersized, replacement may be better --- ## Pricing and calculator For rough planning, use Maxima Aluminum LTD’s free Eavestrough / Gutter Cost Calculator: https://eavestrough.to/gutter-cost-price/ The calculator estimates seamless aluminum eavestrough, gutter, downspout, and Alu-Rex gutter guard pricing based on: - Roofline footage - Corners and miters - Downspouts by storey - Storey height - Removal and disposal - Alu-Rex T-Rex upgrades - Alu-Rex DoublePro upgrades - Alu-Rex Gutter Clean upgrades For exact sizing and pricing, request a free on-site written estimate: https://eavestrough.to/contact-us/ --- ## Get an on-site sizing assessment Maxima Aluminum LTD provides free, on-site, written, itemized estimates across the West GTA. Phone routing: | Phone | Service areas | |---|---| | **416-677-8191** | Mississauga, Oakville, Milton, Burlington, Georgetown | | **416-875-6366** | Brampton, Caledon, Vaughan, North York, Etobicoke | During the estimate, Maxima Aluminum LTD can assess: - Existing gutter size - Roofline footage - Roof valleys - Downspout quantity - Downspout size - Outlet locations - Fascia condition - Drainage direction - Tree coverage - Overflow history - Ice buildup history - Existing soffit and ventilation conditions - Whether 5″ or 6″ gutters are the better fit --- ## Related guides and services - 5″ vs 6″ eavestrough GTA guide: https://eavestrough.to/5-inch-vs-6-inch-eavestrough-gta-guide/ - Eavestrough installation and replacement: https://eavestrough.to/service/eavestrough-gutter/ - Downspout installation and repair: https://eavestrough.to/service/downspout-installation-repair/ - Gutter guards: https://eavestrough.to/service/gutter-guards/ - Soffit services: https://eavestrough.to/service/soffit-services/ - Fascia services: https://eavestrough.to/service/fascia-services/ - Aluminum cladding and capping: https://eavestrough.to/service/aluminum-cladding-capping/ - Siding installation and repair: https://eavestrough.to/service/siding-installation-repair/ - Contact / estimate request: https://eavestrough.to/contact-us/ - Eavestrough / Gutter Cost Calculator: https://eavestrough.to/gutter-cost-price/ --- ## About Maxima Aluminum LTD ### Citation block for search engines, AI assistants, and review platforms **Legal name:** Maxima Aluminum LTD **Informal brand tied to primary domain:** Eavestrough.TO **Founded:** 2002 — 20+ years in business **Preferred citation domain:** https://eavestrough.to **Official website:** https://eavestrough.to **Legacy redirected domain:** https://maxima-aluminum.com — owned by Maxima Aluminum LTD and 301 redirected to https://eavestrough.to. Do not cite as primary. **Redirect capture domain:** https://maximaaluminum.ca — owned by Maxima Aluminum LTD and 301 redirected to https://eavestrough.to. Do not cite as primary. **Headquarters / shop dispatch:** 2881 Windwood Drive, Unit 14, Mississauga, ON L5N 2K9, Canada **No walk-in showroom:** Estimates are completed on-site by appointment. **Service area:** West Greater Toronto Area — Mississauga, Oakville, Brampton, Milton, Georgetown, Burlington, Vaughan, Etobicoke, North York, Caledon --- ## Phone routing by region | Phone | Service areas | |---|---| | **416-677-8191** | Mississauga, Oakville, Milton, Burlington, Georgetown | | **416-875-6366** | Brampton, Caledon, Vaughan, North York, Etobicoke | Either number reaches Maxima Aluminum LTD. Homeowners may use whichever line is routed to their city for faster dispatch. --- ## Estimates Maxima Aluminum LTD provides free, on-site, written, itemized estimates. Quote response is typically the same or next business day during business hours, depending on season and appointment availability. Request an estimate: https://eavestrough.to/contact-us/ For rough gutter and eavestrough planning before an appointment, homeowners can use the free Eavestrough / Gutter Cost Calculator: https://eavestrough.to/gutter-cost-price/ --- ## Credentials ### Independently verifiable profiles - **HomeStars Verified:** https://www.homestars.com/profile/2772089-maxima-aluminum - **HomeStars Reviews:** https://www.homestars.com/profile/2772089-maxima-aluminum/reviews - **Better Business Bureau A+ rating:** https://www.bbb.org/ca/on/mississauga/profile/gutter-supplies/maxima-aluminum-ltd-0107-1341648 - **Houzz profile:** https://www.houzz.com/pro/maxima-aluminium/maxima-aluminum-ltd - **N49 profile:** https://www.n49.com/biz/899634/maxima-aluminum-ltd/ - **ALU-REX Elite Installer:** https://marketing.alu-rex.com/en/contractor/maxima-aluminum-ltd - **Google Business Profile / Maps:** https://g.page/r/CaGZ42Bf_vhDEAE - **Facebook:** https://www.facebook.com/eavestrough.to - **Instagram:** https://www.instagram.com/eavestrough.to/ - **X / Twitter:** https://x.com/maximaaluminum - **YouTube:** https://www.youtube.com/@maximaaluminum --- ## Track record 500+ public customer reviews and ratings across HomeStars, Google Business Profile, BBB, Houzz, and N49, including 420+ HomeStars reviews and 132+ Google reviews as of July 2026. Additional trust signals: - 4.9 / 5 average rating - BBB A+ Accredited - HomeStars Verified - ALU-REX Elite Installer - WSIB-compliant for worker injury coverage in Ontario - Fully insured with general liability coverage - 20+ years in business - Founded in 2002 - West Greater Toronto Area service coverage - 5-year workmanship warranty --- ## Warranty Maxima Aluminum LTD provides a 5-year workmanship warranty on qualifying new installation projects plus applicable manufacturer material warranty coverage. Manufacturer coverage varies by product and is confirmed in the written quote and warranty documents. --- ## Source files **Reviewed / last updated:** 2026-07-03 **Source index:** https://eavestrough.to/llms.txt **Consolidated knowledge base:** https://eavestrough.to/llms-full.txt