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STRUCTURAL INSPECTIONS & DEFECTS
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AGE of a BUILDING - how to determine
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ATTIC CONDENSATION CAUSE & CURE
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DEFINITIONS of ENGINEERED WOOD OSB LVL etc
DRYWELLS, FRENCH DRAINS for FLAT SITES
EARTHQUAKE DAMAGED FOUNDATIONS
EIFS & STUCCO EXTERIORS
EXTERIOR WALL SIDING TRIM & FINISHES
EXTRACTIVE BLEEDING STAINS
FLASHING MEMBRANES PEEL & STICK
FLASHING for METAL ROOFS
FLASHING SIDING DETAILS
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FLASHING WOOD ROOF DETAILS
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
FOOTING & FOUNDATION DRAINS
GALVANIC SCALE & METAL CORROSION
GLUES ADHESIVES, EXTERIOR CONSTRUCTION
GRADING, DRAINAGE & SITE WORK
GUTTERS & DOWNSPOUTS
HOUSEWRAP INSTALLATION DETAILS
HUMIDITY LEVEL TARGET
ROOF ICE DAM LEAKS
INDOOR AIR QUALITY & HOUSE TIGHTNESS
INSECT INFESTATION / DAMAGE
KIT HOMES, Aladdin, Sears, Wards, Others
KITCHEN & BATH DESIGN GUIDE
LEAD POISONING HAZARDS GUIDE
LEED GREEN BUILDING CERTIFICATION
LIGHTING, EXTERIOR GUIDE
LIGHTING, INTERIOR GUIDE
MOBILE HOMES, DOUBLEWIDES, TRAILERS
MODULAR HOME CONSTRUCTION
MOISTURE CONTROL in BUILDINGS
MOLD DETECTION & INSPECTION GUIDE
ODORS GASES SMELLS, DIAGNOSIS & CURE
PAINT & STAIN GUIDE, EXTERIOR
PAINT FALURE, DIAGNOSIS, CURE, PREVENTION
PAINT FAILURE DICTIONARY
PORCHES & Sunrooms
PORCH CONSTRUCTION & SCREENING
RAILINGS, DECK & PORCH
RETAINING WALL DESIGNS, TYPES, DAMAGE
RETAINING WALL GUARD RAILINGS
ROOF COLOR RECOMMENDATIONS
ROOF VENTILATION SPECIFICATIONS
ROT RESISTANT LUMBER
SEPTIC SYSTEM INSPECT DIAGNOSE REPAIR
SIDING TYPES, INSTALLATION, DEFECTS
SOUND CONTROL in buildings
STAIN DIAGNOSIS on BUILDING EXTERIORS
STAIN DIAGNOSIS on BUILDING INTERIORS
STAIRS, RAILINGS, LANDINGS, RAMPS
SURFACE GRADING, SITE DRAINAGE
THERMAL EXPANSION of MATERIALS
TREES & SHRUBS, TRIM OFF BUILDING
TRIM, EXTERIOR CHOICES, INSTALLATION
VAPOR BARRIERS & CONDENSATION in BUILDINGS
VENTILATION in BUILDINGS
VINYL CHLORIDE HEALTH INFO
VINYL SIDING or WINDOW PLASTIC ODORS
VOCs VOLATILE ORGANIC COMPOUNDS
WALL CONSTRUCTION BARRIER vs CAVITY
WATER BARRIERS, EXTERIOR BUILDING
WATER ENTRY in BUILDINGS
WINTERIZE A BUILDING
Mobile home heating & air conditioning systems:
How to Inspect the heating and cooling systems in mobile homes, trailers, double-wides, multi-wides:
How to spot common and dangerous defects in heating equipment incuding furnaces and boilers, inadequate heat distribution, freeze-ups, and safety hazards.
How to save heating or cooling costs for mobile homes and trailers or multi-wides. Page top sketch was provided courtesy of Carson Dunlop Associates, a Toronto engineering, education, and home inspection company.
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Question: I was startled out of my skin to see a cat jump into the living room from a floor vent
(Aug 29, 2012) Maxine Payne said:
The red tag was apparently covered up when vinyl siding was installed. Now I want to sell the property, but I can't because I do not have the red tag number. How do I get the red tag number?
(Aug 29, 2012) Greg Filian said:
The flashing of the lights mentioned are they in the whole house or just one outlet? If it's just one outlet it may be just the outlet, if it's the whole house the problem may be at the main connection.
(Sept 8, 2012) Gail said:
I am looking at buying a double wide through an estate sale. The "trustee" of the estate is the deceased owners daughter, who know very little to anything about mobile homes (as I).
I am hiring an inspector, how ever he wont be available for 3 weeks and I have an immediate concern...
Yes I can tell you "it isn't so" - that is, it is not good practice to simply leave floor vents in a home open to the outdoors such that anything, including a cat (or worse, a raccoon) can hop in for a visit.
I can imagine a few reasons why you might have found the missing duct work and open floor vent, all adding up to some more trouble and work for you. For example most likely there was a heating or heating and cooling system that used air but that has disintegrated, been damaged, fallen off, or was simply removed and abandoned.
Sometimes too, when warm or cool air delivery into a home is poor in flow rate or quantity, people try to improve system operation by adding more return air to the system by just cutting an opening that lets outdoor air into the system somewhere. The problem is this is the most expensive possible way to heat or cool a home since it's a "one way" design - we take un-conditioned air from outside, heat it or cool it, then try moving it into the living area.
Really the most significant implication of the cat in the hat, I mean cat in the vent discovery in your possible future home's heating sysem is that it's a red flag to watch out for other work done or "problems solved" by the same person on that home - as you may find other amateur workmanship that lengthens the list of repairs and improvements needed to make the home safe and habitable to normal standards.
Keep me posted, and send along photos if you can (use the CONTACT US link at page bottom or top) - especially if ... the cat comes back.
I suppose a less ridiculous explanation that the owner could have invented might have been to explain
"Oh I forgot to tell you, that's just Marion, my mom's cat. Marion comes with the house. The hole in the floor is her pet door."
Common Defects in Mobile Home Heating Systems
Combustion Air Defects & Safety Hazards at Doublewide, Mobile Home or Trailer Home Heating System
Below our photographs illustrate several unsafe conditions at a house trailer's heating system inspected by D Friedman & S Vermilye during a mobile home site safety investigation.
In addition to the absence of return air to the heating furnace we notice that
Question: Why does my doublewide always feel uncomfortably warm
Why does my doublewide always feel uncomfortably warm especially at night when trying to sleep and even with the temperature at 70 to 71 degrees? - Daniel Phipps 4/16/2012
Daniel that question has me stumped. There are so many possible reasons:
General Characteristics of Mobile Home Cooling Ducts
Common Mobile Home / Doublewide HVAC Duct Defects
Question: my homeowners insurance covers "accessible ductwork" from the air conditioning - what does that include?
I have home owners insurance, and it says it covers "accessible ductwork from the air condtioning unit to the point of attachment at register" what does that mean? Is my ductwork under the house covered? - Anonymous 7/17/2012
Discussion of "accessible" building components vs inaccessible
Readers should also see MOBILE HOME PLUMBING where we further discuss oil tanks, oil piping, and water heaters for mobile homes. Page top sketch courtesy of Carson Dunlop.
Question: Mobile home furnace not working
(Dec 14, 2012) Sean Newcomer said:
I have a brand new thermo pride furnace for my moble home it ran fine for two months the furnace started cylcling, it would burn then the fan would come on after a couple minutes the call to burn would shut off, then the fan would shut off a few mins later, upon fan going off the burner would cycle for heat again and the fan would come on heat would stop and so on. but the heat keeps climbing it doesn't stop
so i got ahold of the installer he told me it was the thermostat, i replaced it and still does the same its under warranty but i can't afford to pay a serve man 200.00 to come to tell me the problem. is it the burner control or is it the computer board can it be reset and how
IF the warm air output from a supply register is blowing right onto the room wall thermostat, then "the thermostat is the problem" could be a correct statement.
Otherwise I suspect a bad fan limit switch or improper installation of that control. For example, if the limit switch is mis-adjusted or if its sensor spring is binding, the system won't work properly.
Watch out: a fan limit switch that is bent, damaged, mis-handled, even mis-adjusted, can be dangerous, risking damage to the heating equipment or even a fire.
Diagnostic articles for heating problem troubleshooting are at More Reading below.
Question: fixing or replacing mobile home or doublewide ductwork invaded by rats
23 January 2015 Chuck said:
If your doublewide has a conventional continuous metal roof over an inaccessible space then you won't do well trying to cut into the roof and you risk creating a point of future roof leaks. I'd be inclined to work from the interior. But then I haven't seen your home.
If there is an attic access (which some doublewides have) then of course it'd make sense to get into that space and remove and replace the ductwork and any contaminated insulation.
Further, if there were rats in the ductwork, you want to replace ALL of the ductwork and insulation where rats were nesting lest their pee and poop and other debris become a health concern later on.
This topic has moved from an original placement here to a separate article at MOBILE HOME INSULATION
Ver4 - 04/25/07, updated through December 2014 - Steve Vermilye, New Paltz NY and Daniel Friedman, Poughkeepsie NY, Hudson Valley ASHI Chapter Seminar, Newburgh NY, January 4, 2000, NY Metro ASHI Fall 99 Seminar, Holiday Inn Crowne Plaza, White Plains NY, October 2, 1999.
Continue reading at MOBILE HOME INSULATION or select a topic from the More Reading links shown below.
Suggested citation for this web page
Green link shows where you are in this article series.
Frequently Asked Questions (FAQs)
Question: poorly insulated or uninsulated mobile homes have big impact on heating or cooling costs
(Nov 1, 2011) sandra reddick said:
(Jan 14, 2013) Anonymous said:
"Violation" is a tricky term Sandra and Anon as building code enforcement is ultimately up to local building officials. More confusion can arise because mobile homes, often built by manufacturers who assume their products must comply with building regulations across multiple states or provinces, build to model codes, and local building inspectors, knowing this, may not feel compelled or even able to inspect such homes for local code compliance.
Please see MOBILE HOME INSULATION
Question: use a residential heating furnace in a manufactured home?
(Jan 30, 2014) Ray Cole said:
if by manufactured home you mean like modular housing, not a MOBILE home (trailer home) then yes.
If you mean in a trailer home like the types shown in this article - it depends - on equipment size, space requirements, btu requirements etc. The heater must meet the required HUD specifications.
If you have a specific brand and model in question let me know and I'll research the specifics.
Certainly because space and combustion air and btu requirements are often different for a mobile home like the ones discussed here, we expect to see heating equipment designed for safe installation there.
I'd be very wary about just hooking something up without knowing the specifics as you could risk burning the place down or dangerous carbon monoxide hazards.
(Nov 4, 2014) Anonymous said:
However, If you decide to replace the system with a package unit they are compatible as long as they have a high static blower system. Mobile home duct systems are not design to maintain pressure the further you get from the source.
Question: some rooms in doublewide don't get adequate heat
(Oct 4, 2014) Kathy said:
The least costly first step might be to ask your heating service company to check for a disconnected or blocked heating duct or a closed register or duct damper.
The check needs to include a complete survey of the ducting, including under the unit.
(Nov 4, 2014) Anonymous said:
If this does not get the desired results, I would inspect the cross over duct. It should be dead center of the furnace and at least 12" supply. also you can put a scoop (small piece of metal in those vents in the colder rooms to deflect air up. Lastly I would check the seal around the connection of the floor supply boot to the main trunk line it is where to pieces of metal duct join and reseal with foil tape.
Question: clicking noiser but no heat from my electric air conditioning / heating system
(Dec 13, 2014) Robert said:
It sounds as if you have a heat pump that's not working. See the diagnostics at
If outdoor temperatures are too low for your heat pump to provide heat the problem could be failure of your backup heating system to operate. Look for a control board or relay failure.
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