In general, seller has no duty to disclose defects of his for-sale house. It is your responsibility to find out whether the house is suitable for you to buy. If you asked the particular question, such as whether the house leaks, nd the seller knew the problem but cheated you, you might have a case against the seller for misrepresentation. Otherwise, he is not responsible for the leaking. Of course, it is not the lawyer's duty to find out all defects of the house you intended to buy.
If you have insurance, fix the prolblem and let the insurance pay for the cost.