怎样要求邻居锯树

邻居家有两棵非常大的树，两年前大风，一大截树枝倒我家的院子里，给他们说了,人家说贵不弄，一个月前大风刮倒了树，把他家房子劈成了两半，引发火灾，着实吓着我了，现在他家似乎还是不打算处理另外一颗树，怎么办

Give written notice to your neighbor about your concern of the issue and keep that record. If they still take no action and anything happen in the future their home insurance or themselves will need to cover the damage on your side.

一棵树倒了不能证明另一棵树有风险，倒了保险公司会互相扯皮的。最保险的方法是去找个arborist做评估，证明这颗树有风险，拿着报告去要求他砍。