New furnace causes icing and frost issues

Q. I am having frost and icing problems. My furnace is two years old and several HVAC guys and a contractor have been unable to figure out the problem.

I am wondering if the furnace was installed correctly. The problems, in a nutshell, are:

• The flue from the furnace is icing up on the roof.

• There is frost forming inside the house on the ceiling in the second floor.

A. Efficient furnaces should not have their exhaust vented through regular chimneys or a new chimney going through the roof. The gases they emit are cool compared to older, nonefficient furnaces and, traveling through a cold chimney and cold spaces, they freeze up.

These newer furnaces should be vented through the rim joists of the first floor.

Q. The last few months we have experienced burning and itchy eyes after showering. After much investigation, we have decided that it is our water. What water filter do you recommend for the shower head and bathroom vanity sink? Since only our eyes are affected, we do not want to filter the water system coming into the house.

Now, with cold weather, this is exacerbating dry eyes and causing constant irritation.

A. There may be some allergens in the water that cause a histamine reaction affecting your eyes.

Consider having a water specialist analyze your water and recommend an appropriate filtration system.

Q. When a basement floods in cold temperatures and it freezes, what damages or concerns are there for the foundation itself? And are there any other concerns I should worry about?

A. What is causing the basement to flood in cold weather? Was the heat in the house shut off and the water pipes froze and burst or are you referring to the basement flooding from external causes? And if so, how did the water get in to the extent of causing a flood?

If the water leaked from external causes, how did so much water get in the basement and freeze? Was the heat in the house off?

In that case, the water pipes are in danger of freezing as well unless the water was shut off and the system properly drained by an experienced person.

Damage to the foundation is unlikely if the foundation is made of poured concrete unless the problem is exasperated by extremely cold weather over an extended period of time and poor grading around the foundation is the cause of the leakage.

Block foundations are more vulnerable and can suffer extensive damage from frost pressure. As you can see, I need a lot more information to be more specific.

Q. I have a serious black mold problem that has caused structural damage and I don't know where to begin. About two years ago I started noticing some small signs something was going on (a small spot on a living room ceiling, some black showing up on vinyl siding that looked like dirt where the siding met a room jut out). Then when I went to paint a bedroom I noticed some interior drywall damage and the paper just peeled off so I called a roofer and siding contractor. He climbed all over the roof and attic and found nothing. He ripped out the drywall and found extensive black mold. He then went back out and found that when the vinyl siding was installed the contractor did no caulking. Since it was winter when the problem was found, we decided to have him caulk the exterior, rip out the damaged drywall and affected insulation and seal the area back up until spring when we can address it from both inside and outside.

See the attached images from the upstairs bedroom above the living room. You can see that several two-by-fours are structurally compromised and the wall sheathing is gone.

What you can't see is that the subfloor is also rotted, and that it appears to have spread into the adjoining bedroom and probably the cavity between the living room ceiling and bedroom floor above it, and probably down to the first floor exterior living room wall.

Fortunately we have not gotten sick and no one uses these rooms and the vinyl siding was only installed on one side of the house, which we had done 20 years ago when we first moved in.

The rest of the house has the same original aluminum siding from the builder. What do I do next? Who do I hire? Do I need permits? Should I insist on replacing the two-by-fours rather than encapsulating them? And I am worried about resale. How do I fix this right and satisfy any future buyer that the problem has been fixed?

My husband is not as worried as I am (he does environmental pollution remediation for corporations and is used to seeing nasty stuff) and thinks I am panicking. I am at a loss what to do next and am sick with worry.

A. If you are truly panicking, you are on the right track! You do have a very serious problem, and my guess is that it started 20 years ago when you had the vinyl siding installed since this is the only part of your house affected (you have not mentioned any such problems on the other sides of the house with the original aluminum siding).

The absence of caulking is unlikely to be the cause of such damage as evidenced in your photos. It is more likely that the installation of the vinyl siding was improperly done by inexperienced installers.

Most of the leakage problems I have investigated over decades of inspecting vinyl siding installations were due to improper installation of trim pieces around windows, doors and all other joints with adjacent surfaces.

You should have the vinyl siding checked and any deficiencies corrected. The siding may have to be reinstalled or replaced by an experienced general or siding contractor.

Once this is done, all affected wood - studs, sheathing, subfloor, insulation, etc. - should also be replaced.

A general contractor with extensive experience in remodeling and restoration of damaged structures is the best contractor to hire, and no corners should be cut in performing the repairs.

I cannot answer the question about permits needed. An experienced contractor should know what the local requirements are.

In these days of full disclosure, you will surely be asked to list on the disclosure forms required at the time of sale all the problems you incurred and what was done to fix them. So please make sure you save all photos taken during the repairs and all paperwork pertaining to them.

It may still scare off some prospective buyers worrying about some other hidden damages, but it beats a lawsuit later from some litigious people looking for compensation for "hidden damages" you didn't reveal.

• Henri de Marne, a former remodeling contractor turned columnist and consultant, is the author of "About the House with Henri de Marne" (Upper Access Publishing). He continues to take questions from readers for this column and his website, www.henridemarne.com. Email questions to aboutthehouse@gmavt.net.