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Inspecting, Installing, Repairing Skylights, Windows, Doors InspectAPedia®  -     Guide to energy efficient windows and doors Examples of types of exterior doors, & door defects List & photos of types of windows found on residential buildings Guide to skylights, skylight leaks, repairs, proper installation methods Guide to sloped glazing, guide to vertical glazing Guide to diagnosing and curing leaks at basement windows Window condensation causes & remedies

How to build, diagnose, inspect, install, and repair skylights, windows, doors.

For some home buyers, especially of older homes, un-disclosed problems with windows and doors (leaks, rot, energy loss, operability) can be a real "sleeper" that later turns out to be a source of major headaches and big costs. Our photo (left) shows a lovely antique eyebrow window on a roof in New York state.

At a home inspection in New York we found an entire development in which nearly every wooden window in the 1960's - 1970's homes was badly rotted. The same siding installation company had made the same mistake - hundreds of times.

A flashing error at window tops and sides sent wind-blown rain into the window frame, leading to rot and in some cases termite damage as well.

Windows and doors that are leaky or poorly constructed can be a big energy loser on buildings as well. Here we provide a series of articles on the inspection, diagnosis, installation, and repair of problems at windows and doors on residential buildings.

© Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

Guide to Inspecting, Diagnosing, Repairing Skylights, Windows & Doors

Exterior building doors, with focus on selecting and installing energy-efficient doors are discussed in detail at WINDOW / DOOR ENERGY EFFICIENT, DOE. This photo shows a multi-lite exterior door used at an enclosed porch. Our photo (left) shows an expedient, but insecure means of securing these interior doors. This photo shows rot and damage that will eventually occur if a sliding glass door threshold is not kept flashed and sealed.

Basement walkout doors were originally usually site-built using sloped wood (photo, below left); if your basement door is in as terrible shape as the unit shown here, the worry about leaks into the building basement should take second place to the immediate life-safety hazard of a rotted door like this one. Modern basement walkout doors are purchased as a pre-fab steel unit from manufacturers such as Bilco™ (photo below right) and may be set on a site-built or pre-fabricated masonry stairwell.

What are the Basic Types of Windows and What are the Names of Parts of Windows?

Our sketches of basic double-hung window parts (above left and below left) appeared in Basic Housing Inspection and later in other window guides. Our sketch of repair of window sash cords and weights shows how older double-hung windows operated with sash weights and came from the same source.

Awning-type windows operate by a crank and open outwards from the bottom, hinged at the sash top. Basement windows vary among many of the styles listed here, but because they are normally close to or even below ground level, special installation detail and attention to handling of roof spillage are critical to avoid leaks, rot, and indoor water and mold problems. See WINDOW LEAKS INTO BASEMENT. Bay windows project out from the building wall and may incorporate both fixed vertical glazing and operable sashes of any type, usually double-hung or casement style. If the roof over a bay window is not maintained, or if the window is not properly installed, leaks and condensation are likely. This bay window uses fixed center glass and double hung sashes at either side. Casement-type windows also operate by a crank, but are hinged at one side and open outwards like a door.

Dormers (photo at left) are not a window-type but rather are an expansion of space under the roof area of a building. Nearly any type of window can be installed in a dormer. Dormers as a means of gaining space and light to make an attic area into living space have been around for a long time. Double-hung windows use two moveable sashes, an upper and lower unit that slide past one another. When inspecting a home for window problems don't assume that all new or recently-installed sashes are operable without doing some actual testing. Eyebrow windows (see photo above) may be fixed or operable and are built protruding through the slope of a roof surface. Eyebrow windows may also appear as small peaked installations but the classic is rounded such as we show above. An "eyebrow" window is a miniature dormer in essence but requires less supporting framer than a larger dormer. An eyebrow window is not a dormer. Fixed glass windows may be vertical or sloped. See VERTICAL GLAZING DETAILS for an example. Also see SITE BUILT DOUBLE GLAZED WINDOWS.

• Single-hung windows are similar to double-hung units but only one sash, usually the lower one, is movable.
• Slider type windows use sashes that slide horizontally like "bypass doors", one sash passing the other on the inside or outside. These slider widows on a log cabin we renovated in Minnesota were site-built, leaky, and replaced entirely.
• Skylights are an example of sloped glazing, normally built into a roof surface. Skylights may be operable for ventilation or fixed. See SLOPED GLAZING DETAILS and see SKYLIGHT LEAK DIAGNOSIS & REPAIR.
• Storm windows are additional windows, fixed or operable, that are hung or installed over the main window sash to reduce heat loss through the window. A "triple-track" storm window incorporates a movable screen and upper and lower widow sashes. Each layer of glazing added to a window cuts heat loss through the window glass by about one third, but if the window is drafty any energy savings will be lost until the drafts are found and sealed. See AIR LEAK MINIMIZATION and AIR SEALING STRATEGIES as well as ENERGY SAVINGS RETROFIT LEAK SEALING GUIDE.

How to inspect, diagnose, and repair skylights, sloped glazing, vertical glazing, energy-losing windows, and leaky basement windows.

WINDOWS & DOORS articles on window selection, installation, efficiency, leaks, diagnosis, and repair SKYLIGHT LEAK DIAGNOSIS & REPAIR - how to avoid leaks, rot, damage at skylights SLOPED GLAZING DETAILS- proper installation details for sloped windows and skylights SITE BUILT DOUBLE GLAZED WINDOWS - is it worth building your own window frame and installing insulated glass? Sometimes. VERTICAL GLAZING DETAILS - proper installation details for vertical fixed glass windows to avoid leaks, rot, condensation, heat loss WINDOW / DOOR ENERGY EFFICIENT, DOE U.S. Department of energy detailed recommendations for energy savings at windows and doors - supplemented by leaks to articles with additional "how to" details WINDOW LEAKS INTO BASEMENT - the good, bad, and ugly of leaks into basements at basement windows: diagnosis and cure

Here we show two problem windows at building basements. If your basement windows seem to be points of leakage into the building, see WINDOW LEAKS INTO BASEMENT.

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Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

EXTERIORS of BUILDINGS
AGE of a BUILDING - how to determine
ALGAE, FUNGUS, LICHENS, MOSS
ATTIC CONDENSATION
BASEMENT WATERPROOFING
BOOKSTORE - EXTERIORS
CHIMNEY INSPECTION DIAGNOSIS REPAIR
DECK & PORCH CONSTRUCTION
DECK COLLAPSE Case Study
DECK FLASHING LEAKS, ROT Case Study
EARTHQUAKE DAMAGED FOUNDATIONS
ENERGY SAVINGS in BUILDINGS
ENVIRO HAZARDS
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
FOUNDATION WATERPROOFING
HEAT TAPES & CABLES on Roofs for Ice Dams
HOUSEWRAP AIR & VAPOR BARRIERS
LEAD POISONING HAZARDS GUIDE
LEAD TEST KIT for HOME USE
LOG HOME GUIDE
LIGHTNING PROTECTION
MOISTURE CONTROL in BUILDINGS
MOLD DETECTION & INSPECTION GUIDE
MVOCs & MOLDY MUSTY ODORS
ODORS & SMELLS DIAGNOSIS & CURE
PAINT & STAIN GUIDE, EXTERIOR
PORCHES & Sunrooms
ROOFING DIAGNOSIS INSPECTION & REPAIR
SEPTIC SYSTEMS
SHEATHING, Gypsum board
SHEATHING Homasote & Other Board
SHEATHING, OSB
SHEATHING, Plywood
SHEATHING, FOIL FACED - VENTS
SIDING, ASBESTOS CEMENT SHINGLES
SIDING EIFS STUCCO
SIDING HARDBOARD
SIDING VINYL
SIDING WOOD
STAIN DIAGNOSIS on Building Exteriors
STAIN DIAGNOSIS on Indoor Surfaces
STAIRS, RAILINGS, LANDINGS, RAMPS
STUCCO OVER FOAM INSULATION
TERMITES, ROT
THERMAL EXPANSION of MATERIALS
THERMAL MASS in BUILDINGS
THERMAL MASS in UPSTAIRS
VAPOR BARRIERS & AIR SEALING at BAND JOISTS
VAPOR BARRIERS & CONDENSATION in BUILDINGS
VAPOR BARRIERS & HOUSEWRAP
VAPOR CONDENSATION & BUILDING SHEATHING
VENTILATION in BUILDINGS
WATER ENTRY in BUILDINGS
WIND TURBINES
WINDOWS & DOORS
  SKYLIGHT LEAK DIAGNOSIS & REPAIR
  SITE BUILT DOUBLE GLAZED WINDOWS
  SLOPED GLAZING DETAILS
  VERTICAL GLAZING DETAILS
  WINDOW / DOOR ENERGY EFFICIENT, DOE
  WINDOW LEAKS INTO BASEMENT
WINTERIZE A BUILDING
WOOD Burning Heaters Fireplaces Stoves

• Basic Housing Inspection, US DHEW, S 352.75 U48, p.144, out of print, but is available in most state libraries; New York State version, ca 1955, source of our window parts and window repair sketches.

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

• Our recommended books about building design, inspection, and repair, and about indoor environment testing, diagnosis, and cleanup are at the InspectAPedia Bookstore.
• "Weather-Resistive Barriers", how to select and install housewrap and other types of weather resistive barriers, U.S. DOE
• Masonite Woodruf® Roofing or Masonite OmniWood® Siding Lawsuit Settlement Notice - PDF file
• ...

More Information on Building Diagnostic Inspections and Repairs

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The Mold Information Center: What to Do About Mold in Buildings, When and How to Inspect for Mold, Clean Up Mold, or Avoid Mold Problems

Use this simple, economical mold test kit by following our instructions on how to collect and mail mold samples to our lab

Environmental Inspection, Testing, & Diagnosis On-Site IAQ, Gas, Air Testing, Mold Investigation, Sick Building Diagnosis, Lab Services, & Remediation Plan Preparation - indoor air quality testing, problem source determination, supporting lab work, written remediation plan addressing removal of environmental and other hazards and prevention of their recurrence.

Building Inspection, Problem Diagnosis, Forensic Investigation & Testing, Repair Consulting

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