It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "None of you should forbid his neighbour from placing a beam on his wall." Then he said: Why do you turn away from it? By Allah, I will certainly keep narrating this hadith.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلح / 11374