Buildings insurance with excessive excess

Campaigning and Policy

I own /let a ground floor flat (1) in a large block and pay service charges which include buildings insurance to the buildings management company (BMC) I will not name them at present. The flat above (3) had a major water pipe leak this week. All BMC did was turn off the water and then told my property management company - over to them to sort out tenant re-accommodation (no water /electrics), repairs for flooring, walls and decoration etc. Apparently the insurance policy had an excess and BMC would do nothing. When I asked for policy details the excess is £10,000 for water damage! Many other landlords in similar situation may not be aware of the practice of their BMC getting cheap insurance by increasing the excess claim levels. I was not advised/ did not look at the policy until an emergency happened. Liability lies with No3 (owner occupier) but his insurance may not cover damage to my flat because he will be paying service charges and assume he is insured. But there is a lot of sorting out to do - but unlikely to reach £10k. This practice needs to be investigated AND at least landlords made aware to check their insurance details.
If I had a mortgage (not at this property in fact) but would the mortgage provider be satisfied with this level of excess on the buildings insurance? It is really obvious when you see the Policy. Penny Landlord
Policy Excesses
Fire, Lightning, Earthquake, Explosion, Aircraft, Riot & Civil Commotion £500
Strikers, Locked-Out Workers & Persons Taking Part in labour disturbances £500
All Perils excess, unless otherwise stated below: £500
Escape of Water £10,000
Flood £500
Theft & Attempted Theft £500
Subsidence £1,000
Storm £50