Home>Discussions>EXTERIORS>Is a slightly sagging roof normal in old homes?
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Michael
Is a slightly sagging roof normal in old homes?
Michael

I have an 1870 home, and the roof sags a little in the middle. It wasn’t a major concern of mine when I bought it and still isn’t, but it’s something I thought I’d eventually look into. The rafters are about 4”x6” and spaced 24” OC so I’d say they’re properly sized. The thing I never looked at yet is whether or not the wall is pushing out in the center, the interior walls aren’t cracked but it’s all new drywall in that part of the house which I guess is a little suspicious. I’d assume though that considering the house is 150 years old, this might be normal due to some settling over the years. 

HandyAndyInMtAiry
Re: Is a slightly sagging roof normal in old homes?
HandyAndyInMtAiry

Michael,

It is usually nothing to worry about. But you state that you replaced all the lathe and plaster with sheetrock. That is something that you do not want to do on an old structure. The architecture of an old house requires the lathe behind the plaster as structural support. You cannot follow new house design methods on old structures. They are also deisnged to breathe, so you do not want to make the house air tight. If you try, the sheetrock will begin growing mold, since there will be moisture and paper for the mold to eat. This is another reason that you do not want to place plaster with sheetrock. You can raise the ridge beam up and then install collar ties about every other rafter. This will help to give the walls support. Right now the roof is trying to push over the walls, since the support has been removed. Do this type of work gingerly. Do not try to move the ridge beam in one day, raise it a couple millimeters a week. Then nail in collar ties once the roof is up as level as it will go. You will never get it back perfect, but you will be able to add support to the structure.

We live in a house that is older than yours, and I grew up in a Victorian house. I am not sure still why folks replace all the plaster with cheap sheetrock in an older structure. They are not designed for sheetrock.

Andrew

Handy Andy In Mt Airy NC

Michael
Re: Is a slightly sagging roof normal in old homes?
Michael
HandyAndyInMtAiry wrote:

Michael,

It is usually nothing to worry about. But you state that you replaced all the lathe and plaster with sheetrock. That is something that you do not want to do on an old structure. The architecture of an old house requires the lathe behind the plaster as structural support. You cannot follow new house design methods on old structures. They are also deisnged to breathe, so you do not want to make the house air tight. If you try, the sheetrock will begin growing mold, since there will be moisture and paper for the mold to eat. This is another reason that you do not want to place plaster with sheetrock. You can raise the ridge beam up and then install collar ties about every other rafter. This will help to give the walls support. Right now the roof is trying to push over the walls, since the support has been removed. Do this type of work gingerly. Do not try to move the ridge beam in one day, raise it a couple millimeters a week. Then nail in collar ties once the roof is up as level as it will go. You will never get it back perfect, but you will be able to add support to the structure.

We live in a house that is older than yours, and I grew up in a Victorian house. I am not sure still why folks replace all the plaster with cheap sheetrock in an older structure. They are not designed for sheetrock.

Andrew

Handy Andy In Mt Airy NC

I personally wasn’t the one who did it, I believe it was done 40 years ago. The lathe could still be there if all they did was cover it up (I once worked with a contractor who put thin sheets of drywall over heavily damaged plaster). On the subject of mold, I actually have issues with mold on the walls in my bathroom and laundry room which is in a newer addition on the back of the house and has drywall. Obviously a different subject then what I asked but I’m going to try using the glossier “bathroom paint”

HandyAndyInMtAiry
Re: Is a slightly sagging roof normal in old homes?
HandyAndyInMtAiry

You need to cure the problem before covering up the issue. Paint does not kill mold, paint will not even slow it down from growing. Paint will only hide it behind the paint. Mold will still be on the layer of paper behind the paint. There is paper in sheetrock, along with a little bit of moisture and heat, creates a prefect breeding ground. You need to ensure that all water and moisture are removed from the area. Remove and replace all damaged wood, sheetrock, insulation and any other organic material before building back.

Andrew

Handy Andy In Mt Airy NC

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