Threading Question

[Major Tom]

Hello all, I have a class ChunkManager that has a few (supposed to be) asynchronous methods. These methods handle tasks in my game engine such as loading the map blocks (similar to Minecraft) on a different thread so as not to completely halt the main thread (they are lengthy operations)
Here is one of those methods:

void ChunkManager::asyncRenderChunks(){

    boost::thread loadingThread(&ChunkManager::renderChunks,this);
}

Where renderChunks looks like:

void ChunkManager::renderChunks(){
activeChunksMutex->lock();
      for(int z=0; z < CHUNK_MAX; z=z+1)
      {
        for(int y=0; y < CHUNK_MAX; y=y+1)
        {
            for(int x=0; x < CHUNK_MAX; x=x+1)
            {

            activeChunks[x][y][z]->Render(scnMgr);

            }
        }
    }
    activeChunksMutex->unlock();
}

This should work, right? However it crashes when this runs. I have a feeling it has to do with what I do with the thread after it's created, because if I put loadingThread.join(); in the aforementioned method, it works fine, but the main thread is halted because obviously its just waiting for the new thread to finish, effectively bringing me back to square one.
Any advice?
Thanks.