Category Archives: Home Improvement

Flat Roof Ponding

Is It Acceptable to Have Ponding On My Flat Roof?

By Allen Sensel

Moderate Water Ponding

Introduction

There is a lot of speculation with older building designs and how their flat roofs have a tendency to collect pools of standing water referred to as ponding. The purpose of this report is to provide clarity for a commonly misunderstood notion that a flat roof, whether it’s asphaltic built-up, modified bitumen, or any kind of single-ply membrane, should not bear any kind of collection of rain water. I will provide brief examples from the IBC, U.S. Department of Housing and Urban Development, and Factory Mutual, all of whom mandate construction and renovation standards to comply with regional climates,weather patterns, and safety.

Definition

Ponding water, as described by the IBC and recognized by the U.S. Department of Housing and Urban Development, is water that remains on a roof surface longer than 48 hours after the termination of the most recent rain event.

Standing Water

This explanation from the IBC can also point out that directly following persistent rainfall, water is not considered standing until after 48 hours of dry weather, after which, can evaporate efficiently at temperatures above 45 degrees Fahrenheit. Only when the same volume of water exists after this period can there be a concern for potential leaks, providing that the roof system was properly installed.  The U.S. Department of Housing and Urban Development elaborates on how building inspectors approach ponding after an installation:

“48 hours before conducting a physical inspection, check the local weather forecast to see if precipitation is expected. If there has been precipitation within 48 hours prior to your inspection, use your judgement in deciding if observable ponding is due to the recent precipitation or because of an ongoing problem. Keep in mind that some flat roofs are designed to allow ponding.”

Concurrent with the size of the roof, Factory Mutual Global explains rain load on a dead flat roof:

“2.1.1.1.7 Roofs should be designed with positive drainage: however, dead-flat roofs consistent with this guideline are acceptable.”

An older building will lack modern specifications for framing slopes a minimum of  1/4” rise per 12” run. The solution to controlling water flow on a dead flat roof, if ponding is still a noticeable concern after following the aforementioned provisions, is designing a framed slope for positive drainage to scuppers and/or bowl drains.

Resources

“Definitions Supplement.” U.S Department of Housing and Urban Development Real Estate Assessment, October, 2001: 3

“Roof Loads for New Construction.” FM Global Property Loss Prevention Data Sheets, September 2006: 3-5

International Code Council. 2009 International Building Code. 2009

 

 

Cover-Boards: Purpose & Application

by Allen Sensel

Glass-Matt Roof Protection

When putting a low-slope roof together it’s important, as a building owner or engineer, to understand how to control moisture, combat mold, and provide fire protection. Cover-boards offer sufficient roof deck protection that meet these requirement for installing a roof. They can also serve as a purpose for re-covering your roof. These boards provide a clean, smooth surface to attach your next roof system to.

Glass-Mat Roof BoardUSG manufactures Securock, a glass-mat board that can be used on a flat roof for dimensional stability, surface protection, and overall increased lifespan of a structure. When installed correctly, Securock acts as vapor and fire barrier, keeping the roof membrane from developing mold and succeeding in fire standard ratings (rated at the maximum ’10’ with Factory Mutual [FM] Class 1 and a Class A Fire rating with Underwriters Laboratories [UL]). This is a great way to qualify for lower insurance rates as your building is less prone to fire damage.

One of the other benefits to using Securock is its ease of installation. The packaging is efficient and the board utilizes a high-quality, mat-to-core tensile bond, making each piece easy to cut and hand-break. This creates a faster labor work-flow and less of a mess to clean off of the roof surface, which helps to cut cost and keep workers focused on installing a quality roof as a whole.

As a local certified Seattle roofing contractor, we’re all about installing a quality commercial flat roof and so we recommend using USG Securock for our installations. We also specialize in single-ply residential roof systems. Give us a call at 253-445-8950 for a free estimate or drop by our website, http://www.chasenw.com.

Determining Your New Roof System

Selecting Worthwhile Components For Weather-Tight Protection

by Allen Sensel

Today, selecting a new roof system might be as easy as finding the right certified contractor to install it for you. Several questions might come up, like which products and manufacturer to use. Typically, the best approach is to do some thorough research and I’m here to help explain the steps and guide you in the right direction. We’ll talk about picking and choosing the right sheathing, roof metals, underlayment, leak protection, and an asphalt system with their relative components to give your roof a great curb appeal and efficient protection.

 

The first protective layer to any house is typically the sheathing, which you will most often find to be conventional plywood, synthetic decking, or particle board. The sheathing is fastened directly to the rafters, covering your attic or crawlspace. Older houses with shiplap (3 to 8 inch wide, tongue and groove boards) are typically sheeted over to create a solid substrate to nail the layers of your roof to so that the system can qualify for a manufacturer warranty.

 

The purpose of using metals in an installation, is to protect the outermost edges of your roof from rot and to keep running water out of the valleys. Metal is usually 26 gauge and painted white, brown, or black for different accenting options, however, you can also have your metal ordered in other colors to perfectly match your color preferences.

 

Once the sheathing and metals are attached, the next step is applying an underlayment. The two most common types are referred to as #15 or #30 felt paper (referencing 15 or 30 pounds per roofing square [100 ft ²]). This material is asphalt saturated and supplied in long runs, making it cost effective. A far better deck protection would be a synthetic underlayment, like IKO’s RoofGard-SB. This kind of material can greatly increase the life of your plywood deck while keeping moisture from getting into your house.

 


Leak protection is the next critical component to a complete roof. National building code requires it to completely cover any roof section below a 3/12 pitch and along eaves in the northern regions. This helps keep wind-driven rain and standing water from ice dams from seeping into the attic and creating a significant problem. Most certified roofing contractors will, on the other hand, suggest placing this membrane among all critical leak areas of the roof (i.e. along rakes, in valleys, and around skylights and chimneys). IKO utilizes a glass fiber reinforced, self-adhesive membrane called StormShield in their roof systems, which meets most building code requirements and exceeds standard specifications for a quality product.

 

Composition roofing is the last product to top your roof off and is also one of the most noticeable pieces of your house, so choosing a style and color isn’t necessarily the easiest to do. One of the benefits of using a certified contractor is the selection process. Most will help you with the guess work and eliminate your need to dive into some extensive research about product comparison. The style of your new shingle will ultimately affect how your roof stands out. The latest, most popular style is the architectural laminate shingle, like the IKO Cambridge system. The premium designer systems, IKOs Armourshake, Crowne Slate, Grandeur, and Royal Estate can offer your house a long lasting, eye-catching addition to your home. A basic asphalt system is comprised of a starter course along the eaves and rakes, the main field shingles, and hip/ridge cap shingles to accent the prominent peaks. IKO offers an extensive line of products for a wide range of applications to suit your design needs, and a local certified contractor to get the job done right.

 

   As a local certified Puyallup roofing contractor, we’re here to help you select and install a quality roof system, and that’s why we’re a certified ShieldPro Plus+ Installer with IKO Manufacturing, Inc. We specialize in flat roof and composition systems for residential and commercial purposes. Call us at 253-445-8950 for a free estimate or drop by our website at http://www.chasenw.com.

 

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Metal Roofing

Why A Metal Roof Is Cost Effective vs. Asphalt Roofing Shingles

Metal Roofing

Before you write off a new metal roof as being too expensive, read this article, it might save you a lot of money. Price is the bottom line for most people when deciding what type of roofing system they will have installed on their homes. What most people do not factor in when considering the cost of a new roof, is how long the roof is going to really last, and how much will it cost to replace the roof in the future. After all, the cost of asphalt based roofing shingles are consistently rising because they are a  petroleum product. In fact the asphalt roofing or shingle industry follows the same pattern as the gasoline industry. That is why metal roofing  has become very popular for residential use in the last decade. Here in Tacoma, Puyallup, Kent and the surrounding cities we have seen the metal roofing trend pick up incredibly in the last 10 years.

The cost of asphalt roofing vs. metal roofing:

The actual roof life of a shingle is determined by the weather conditions, proper installation and roof maintenance. Depending on what type of composite or architectural roofing shingle you choose, your roof can last between 12-27 years. A new metal roof, when properly installed can last well beyond 50 years. If you consider those timelines you will see that an asphalt roof will need to be replaced 2-3 times if not more, before a metal roof will need replacing. Calculating the cost of your re-roof should be examined beyond your immediate need if possible. If you are going to live in your home for a long period of time, or the house is an investment like a rental, you will pay up to 3-5 times more re-roofing with composition type roofing shingles.

Metal is not only superior in its protection of your home, it truly is the economical route of re-roofing when considering “the long run”. Good financial decisions are never made looking at your immediate need, this principal applies to roofing your home as well.

If you live in our service areas of Tacoma, Puyallup, Renton or the surrounding cities, and would like more information on metal roofing please give us  a call. Estimates are always free. You can reach us by filling out our quick estimate form or by calling us at 253-445-8950.

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Chase Construction North West, Inc is a factory trained and certified installer of Custom-Bilt Metal’s products.