My best advice: don't do it. You are lucky to know about this before you sign... We bought a house which was an estate sale (no info, no warranty). During big thunderstorms, water gets in where the wall meet the floor. We had gutters installed, regraded, installed a sump pump... about once or twice every summer, water gets in... the neighbor (who has the house attached to ours; it is a semi-detached house) had an expensive french drain job done, but still gets water. This is not a problem with a simple and cheap fix, believe me. A clear crack would be a much easier thing to fix. We are now looking into inside drains, but the opinions are very mixed on the possible chances of succes (after many thousands of dollars...). Our basement is not suitable for any permanent livable space. We store things down there, but everything has to be on some sort of shelve at least a couple of inches from the floor... This is a constant source of aggravation for us. Everytime it rains, I am afraid water will get in the basement. I would have never bought the house if I had known. It will also be a big issue at resale. My 2 cents, Lyne

That's not the consequenses of not maintaining grout. That's more like a problem of flooding a time or two. Even with sealer, grout is not meant to be waterproof, or even water resistant. However, whater normally won't get on the floor in any kind of volume to be able to do that. What gets on the floor will absorb into the joints, but them evaporate right back out. You can put a waterproofing membtane down under the tile, but the floor won't really be completely waterproof unless the waterproofing laps up the walls 2-3", and goes UNDER the tub, which 99.9% of the time is highly impractical. But it WILL provide you with some measure of protection. That said, When I built my own home years ago, I never waterproofed the floors, and at the time, I had 4 children, ages newborn to 10 years old, and let me tell you, at bath time, that floor got soaked, and still never got to that point, so either you had repeated flooding, or unnoticed leakage from the toilet.

Renovator, was a comment removed? Because other than where you started, down, I don't see anybody ridiculing (or maybe you were talking about me? where I specifically said, IMO, and specifically addressed the question of whether or not they should have walked away?) Now, it has been side-tracked. But I don't think it had been until that point. Your answers on this forum are very helpful, but sometimes very objective. This person specifically asked both an objective and subjective question. They will get subjective answers. This person also has not stated, at all, where in the world they are located. And, whether mold might be a normal thing in their environment (to which I'd say, mold is everywhere, even deserts will have some sort of fungus growing there. It is the nature of nature). To say that those with asthma, etc could have problems even if it is non-toxic, while true, is misleading. Those folks will have problems no matter how their house is constructed in certain environments/ localities in the world. The OP said there was nothing found wrong with the ventilation and the suspected source was prior to the build and final construction. HOW MUCH MOLD (do you have a picture)? Finally, the usual way to remediate mold is actually to not use bleach (only). Mold remediation companies know what to use and would be better to hire than trying to DIY it and assume that you know that "bleach kills everything". I do second the suggestion to get a second opinion from another mold remediation company. (Just remember they will be interested in selling their services to you). However, I suspect at this point, in order to do that, you will need to re-enter contract with these sellers (to get access to their attic) and they may not trust you. Finally, you may want to get the RE opinions on this matter in the buying and selling forum since at least one of your questions pertains to future resale value.

Something you need to consider is that if a professional finds mold, you are required to declare it forevermore regardless what the outcome. You can show proof of treatment at the same time you declare having had mold but noone will give you guarentee that the house is mold free after the abadment is done. You stated that it's been said "all homes have mold" which I don't doubt. With only two small areas of concurn,I would be satisfied with a diy kit and following diy cleaning instructions if any was found. It is possible to live in a house for a lifetime without ill effect eventhough it has mold,lead based paint and asbestos all three. The material must be disturbed before it can be inhaled or ingested. I take nessary precautions like wearing resperator during demolition or restricting children from areas suspected to have lead paint until passed the age of chewing on everything they can. I also highly reccomend high effeciency hvac filters for general good health and equipment protection.