If I understand this correctly, your total outstanding on your flat is �51,000.
You can take out a bridging loan (we did this to purchase our current property) but it WILL cause you sleepless nights.
The brief way it will work is as follows:
The Bridging company will pay off the second loan (�18,000). They will also lend you a further �60,000. This means you will owe them �78,000. They will charge you a fee of about 1.5% (�1170) which can be added to the loan.
The monthly interest would be 1.5% per month and therefore repayments would be just under �1000.
With most bridging, they would roll this money up (ie keep adding it on to the money outstanding) but they will usually only do this up to 75% of the equity of your home less first mortgage outstanding (in your case this is �79,000).
Without any further security, you would have to service the loan.
Most bridging companies will have a minimum of 3 months interest and some have exit fees.
This means that to borrow they money required (if you sold within 3 months) would cost you over �4000.00. And of course, if a similar instance occurred with the buyer, it could take another 3 months and another �3000.
As I said, I can empathise as I have been there before - we were lucky since we completed within 6 weeks. HOWEVER, the people who moved in subsequently fell out and put the house back on the market - and it stood there for almost a year!
If you want to talk more or want further advice, please feel free to contact me (Vic) - contact details are on our website:
http://www.allianceandgeneral.com