You did not mention the types of weeds you are trying to control and where you are placing the cardboard beside the house. If you are trying to control weeds next to the foundation of the house, it is recommended to place a thin layer of mulch around the foundation to keep the soil covered.  If the weeds are not perennial weeds like thistle, a mulch should take care of the weeds. 

 You can use different methods to smother weeds/grass such as unwaxed cardboard or several layers of newspaper. You can cover with several inches of mulch or compost. Keep the cardboard away from the foundation. Surprisingly, rocks actually make the soil more moist and not recommended around the foundation of a house. It is okay to leave a very thin layer of mulch around the foundation to keep the soil covered.

In general, termites are a native insect and a normal part of the environment. There are usually in everyone's yard. A reason to be concerned is, if you were seeing evidence of termites or winged termites in the house. The most important preventive measures you can take to make your home inhospitable to termites are eliminating any direct contact between wood and soil and reducing moisture in and around the house. Make sure water drains away from the foundation. Repair any leaky gutters and the roof and plumbing are free of leaks. Make sure condensation from A/C or humidifiers drips into a receptacle that does not moisten wood, wall board, plaster, or insulation. 

Here is more on managing weeds without chemicals https://extension.umd.edu/resource/manage-weeds-without-chemicals

Marian