This is the highest monthly total since July’s 2009 total of £14bn and is the highest monthly total for August since 2008 which was at £19.3bn.
Gross lending for the year is currently at £90.1bn, 66.3% of the total £135.7bn lent in 2010.
Bob Pannell, chief economist at the CML, said: “Much of the recent variation in monthly lending figures appears to have reflected seasonal factors, with the underlying picture being one of activity levels that continue to be subdued but broadly stable.
“The August performance more or less offset the weaker than expected July figure. Taking July and August together, lending h as shown little change on the same months of 2009 and 2010.”
Richard Sexton, director of e.surv chartered surveyors, said: “The figures are a mirage and don’t reflect the true state of the mortgage market.
“Vince Cable said yesterday we are in the midst of the economic equivalent of war, and lenders must feel like they’re under attack from all fronts.
“They can’t go on the offensive and start lending in greater volumes over the next few months while they are so busy defending against a barrage of weak economic growth and requirements to hold up to 20% capital.
“And an assault on so-called casino banking, institutionalised by the Vickers report, will further limit the capacity of our major banks to increase their loan books.
“As a result, they are focusing on targeting borrowers with big deposits, leaving lower income buyers in the lurch.
“Their higher loan to value products are nothing more than a low volume smokescreen. Before 2008 over one-fifth of all lending was to borrowers with a deposit of under 15%, now it is less than a tenth, which gives a stark indication of just how suppressed the mortgage market is.”
David Whittaker, managing director of Mortgages for Business, added: “Increased activity levels among investors and professional landlords boosted gross lending in late summer.
“With interest rates set to be kept low for at least another year and the rental market growing stronger by the day buy-to-let investors have capitalised on low property prices and high yields.
“While lending to first-time buyers remains subdued thousands will remain reliant on the private rental sector and landlords will continue to take advantage of the opportunities to increase their presence in the market.”
David Brown, commercial director of LSL Property Services, said: "August's pick-up must be put into the context of a more subdued mortgage market in July, where some mortgage activity was delayed until the following month.
“Nevertheless, the mini bounce back demonstrates that lenders do have the appetite to lend despite the challenging economic environment. Demand for mortgage finance, too, has improved, with buy-to-let investors and home buyers with sizeable deposits looking to take advantage of historically low rates on offer.
“However it's difficult to see a double digit percentage improvement in the mortgage market being sustained over the medium term.
“The current turmoil in the markets, combined with many banks' need to repay their debt to the government, makes it difficult to foresee them being in a position to significantly increase their level of funding to would-be mortgage borrowers.”