Rusty steel beams and damp basement

Hello dear people,

Today we looked at a house that we might want to buy. It was built in 1900. Many things have been renewed in the last 20 years, such as the roof, heating, exterior paint, etc. Allegedly, the basement exterior wall has also been insulated. In the basement, I took the following pictures:







There you can see, well, probably the usual brickwork for the time and especially a quite rusty steel beam. I know remote diagnosis is difficult, but what costs might possibly come my way? In the worst case, will a new beam be installed, or is the entire building possibly beyond repair? In one of the basement rooms, there was also mold on the wall.

Generally, can such a house still easily last another 100 years, or is that rather unlikely?

As always, I have no idea about house construction and ask you for your opinions. Thanks!

Would recommend including an expert specialized in old buildings and having the good piece examined thoroughly again if you are otherwise sure about the purchase.

I would recommend that too. Better safe than sorry, and the money for the [Gutachter] is certainly not a wasted investment for houses of that age.

I see nothing in the photos that would not be generally expected for a house of this construction period. If the beams are not deeply corroded, they can be derusted and protected against rust, fulfilling their function for a long time. The "mold" on the masonry can also be masonry saltpeter, i.e. salt contamination. The moisture in old cellars is mostly condensate from warm, moist air on cold cellar walls, caused by incorrect ventilation, for example in summer.

Basically, a house must be inspected in detail and on site before purchase, from the cellar to the attic. Only then can - after visual inspection - an initial assessment of the condition, the renovation effort, and any desired conversion or expansion measures be given. A purchase consultation also includes the assessment of the building and planning law situation and the examination of a number of documents that should prove to the buyer that the property is free of encumbrances.

The so-called "renewals" of the last 20 years must be viewed very critically based on experience and have rarely been carried out in a truly professional manner – constructive and building-physical – consistent.

I can only agree with . I myself have exactly such a basement ceiling in the front building, built in 1918. The iron beams in my case have been treated with corrosion protection and then painted white. If there were moisture and air causing new rust on the beams, it would be immediately visible by brown discoloration.

A little moisture in the basement is completely normal with the construction method used in my building and common at the time, because it cannot be prevented. However, if you know the cause, you can control the moisture; at that time, we used silicifiers against rising moisture from the rubble stone masonry, and nowadays afaik there are also methods with wax that prevent or at least greatly slow down moisture penetration.

In other words: it will never be, or only with absurdly unreasonable effort, a completely dry basement like in a new building, but as already pointed out, that is probably not the problem. I would be much more interested in how the last renovations in the living areas were carried out.

Best regards Dirk Grafe

Thank you for your expert answers, they help me a lot! I will keep you updated!